CUSTOM TUBE CONSOLES
consoles of the past designed for the future
this program is currently in development
Resistor/capacitor colour code chart
Oscilloscope and probes
Drill and bit
Set of needle files
Set of screwdrivers
Radio Designers Handbook
Component tester (RLC as a minimum)
Solder fume extractor fan
Like all electrical devices, the solder station must be handled with care. The soldering iron and tip can reach high temperatures and these simple safety rules should be followed.
• Keep children out of reach of the soldering station.
• To protect your eyes, use safety goggles.
• Keep flammable material away from the soldering iron
• DO NOT cool iron by dipping it into any liquid or water.
• Always assume that the tip is hot to avoid burns.
• Work in an area that is well ventilated.
• Be careful that the hot soldering iron tip or the barrel of the iron does not come in contact with any electrical cord.
• Do not hold solder in your mouth.
• Wash your hands thoroughly after handling solder.
• Locate soldering iron in an area where you do not have to go around it or reach over it.
Almost every electronic device today has a printed circuit board. Whether you are assembling a PC board or repairing it, you must understand the basics of working with these boards. A poorly soldered joint can greatly affect small current flow in circuits and can cause equipment failure. You can damage a PC board or a component with too much heat or cause a cold solder joint with insufficient heat. Sloppy soldering can cause bridges between two adjacent foils preventing the circuit from functioning. Good soldering requires practice and an understanding of soldering principles. This solder practice project will help you achieve good soldering techniques, help you to become familiar with a variety of electronic components, and provide you with dynamic results.
There are two basic types of solder used in the electronics industry today. They are solder with lead and lead-free solder. They both do the same job of fusing electrical connections, but have slightly different melting characteristics.
Lead-type solder has been the most common for years and is composed of tin and lead. The common ratios are 63/37 and 60/40. The first number is for tin and the second is lead. This solder has a melting point temperature of 360O to 370O. It is recommended that the soldering iron tip temperature be between 600O-700OF.
Lead-free solder is the solder of the future and is recommended for all future uses in soldering applications. The two common lead-free solders are LF96 and LF99. LF99 indicates the presence of 99% tin. The melting point of lead-free is 422O-440OF. It is recommended that the soldering iron tip temperature be between 700O-800OF.
Most solder contains flux in the hollow core of the solder allowing it to be applied automatically when you heat the solder. The flux will remove any oxide film on the metals soldered creating a good metal-tometal contact. This is called “wetting the metal”.
There are three types of solder fluxes: chloride, organic and rosin. In the electronics industry, only the rosin type is used. Rosin flux comes in two types, pure and active. The most reliable is the pure type, since it doesn’t cause dendrites between tracks on the PC board as the active type does. Due to the highly corrosive and moisture attracting characteristics of the chloride and organic type fluxes, they should not be used in electronics.
In order for the solder to adhere to the connection, the metals must be clean and free of nonmetallic materials. Flux in the solder can remove oxides from metal but not other materials like dirt or grease. To remove these, use a small steel brush or fine emery cloth.
When all the surfaces are clean, the metals should have a solid mechanical connection. Wires should be tightly wrapped around each other or to the terminal. This will eliminate large gaps that create weak solder joints. Solder should not be used as a mechanical connection.
Types of Soldering Devices
A number of different types of soldering devices: irons, guns and stations are available today. Irons are used for light to medium work and guns are for medium to heavy-duty work. The station type can range from light to heavy-duty For working on PC boards, irons ranging from 15 to 40 watts are suitable, or a station with a range of 15 to 40 watts. If you use an iron with a higher wattage rating than 40 watt, you may damage the copper tracks on the PC board. The higher wattage irons are best suited for heavy-duty electrical jobs.
The tip is the very important part of the iron. The material that the tip is made from is an essential factor. The soldering iron tip contains four different metals as shown in Figure 3. The core consists of copper. Since the copper is a soft material, it is plated with iron. Chrome plating is used on the area where no soldering takes place to prevent oxidation. Then the tip is plated with tin, because it can be easily cleaned. Today, tips are manufactured in a variety of different shapes
The chisel shape is one of the most common. Having a choice of tip styles allows you to choose the one best suited for your soldering needs. Due to the high heat, removable tips can bond themselves to the heating element if left in place for extended periods of time. Periodic removal of the tip is therefore advisable.
Tip Cleaning A good clean solder tip makes soldering much easier. The tip should be tinned by lightly coating it with solder to prevent it from oxidizing. The tip can become pitted (black spots) from normal use. It is important to clean the tip by wiping it with a wet sponge or rag. For tips that need a good cleaning, the tip tinner and cleaner (should be used. Never use a file or abrasive material to clean the tip. Using such methods will damage the plating and ruin the tip. Do not remove the excess solder from the tip before storing. The excess solder will prevent oxidation.
Proper solder adhesion requires that the metal surface to be free of dirt and grease. The flux only removes the oxides so a brush or rag can be used to clean metal. There are contact cleaners in aerosol cans and other solvents available.
Great care should be taken when repairing or correcting a mistake on a PC board. The metal foil can be easily pulled up or broken from excessive heat. Use the least amount of heat as possible. You can use a desoldering tool, bulb, wick or a station. These tools will remove the solder enabling you to correct the problem.
What Good Soldering Looks Like
A good solder connection should be bright, shiny, smooth, and uniformly flowed over all surfaces. Soldering a PC board
1. Solder all components from the copper foil side only. Push the soldering iron tip against both the lead and the circuit board foil.
2. Apply a small amount of solder to the iron tip. This allows the heat to leave the iron and onto the foil. Immediately apply solder to the opposite side of the connection, away from the iron. Allow the heated component and the circuit foil to melt the solder.
3. Allow the solder to flow around the connection. Then, remove the solder and the iron and let the connection cool. The solder should have flowed smoothly and not lump around the wire lead.
4. Here is what a good solder connection looks like.
Types of Poor Soldering Connections
1. Insufficient heat - the solder will not flow onto the lead as shown.
2. Insufficient solder - let the solder flow over the connection until it is covered. Use just enough solder to cover the connection.
3. Excessive solder - could make connections that you did not intend to between adjacent foil areas or terminals.
4. Solder bridges - occur when solder runs between circuit paths and creates a short circuit. This is usually caused by using too much solder. To correct this, simply drag your soldering iron across the solder bridge as shown.
SOLDERING A poorly soldered joint can greatly affect small current flow in circuits and can cause equipment failure. You can damage a PC board or a component with too much heat or cause a cold solder joint with insufficient heat. Sloppy soldering can cause bridges between two adjacent foils preventing the circuit from functioning.
Electronic components such as transistors, IC’s, and diodes can be damaged by the heat during soldering. Heat sinking is a way of reducing the heat on the components while soldering. Dissipating the heat can be achieved by using long nose pliers, an alligator clip, or a special heat dissipating clip. The heat sink should be held on the component lead between the part and the solder joint.
Soldering Surface Mount Components
1. Using tweezers, place the surface mount component on the PC board pads and secure in place with tape (see Figure 7A).
2. Apply a small amount of solder to the soldering iron tip. This allows the heat to leave the iron and flow onto the foil.
3. Place the iron in contact with the PC board foil. Apply a small amount of solder simultaneously to the foil and the component and allow them to melt the solder.
4. Remove the iron and allow the solder to cool. The solder should have flowed freely and not lump up around the component.
5. Remove the tape and solder the other side of the component.
When soldering the transistors, diodes and integrated circuits, the following procedure may be used:
1. Place the component on the PC board pads and secure in place with tape.
2. Apply a small amount of solder to the soldering iron tip.
3. Place the soldering iron tip on top of the component lead to be soldered and apply solder simultaneously to the lead and the PC board foil.
4. Remove the iron and allow the solder to cool. The solder should have flowed freely and not lump up around the component. After a component is completely soldered, each solder joint should be inspected with a magnifying glass. If the solder has not flowed smoothly, a bad solder joint is indicated. This occurs when the component and pad have not been heated sufficiently. To correct, reheat the connection and if necessary add a small amount of additional solder.
Another way to solder surface mount components is as follows:
1. Apply a small amount of solder to the soldering iron tip
2. Using tweezers, hold the component on the PC board pads.
3. Apply the soldering iron simultaneously to the component and pad and allow the solder to flow around the component.
4. Remove the soldering iron and allow the connection to cool. Tweezers or Pliers Solder Soldering Iron Surface Mount Component Heat Sink
The tip sizes and shapes greatly effects the heating and heat-recovery. Today, tips are manufactured in a variety of different shapes. A tip with a conical shape, is one of the most common.Having a choice of tip styles allows you to choose the one best suited for your soldering needs.
Due to the high heat, removable tips can bond themselves to the heating element if left in place for extended periods. Periodic removal of the tip is therefore advisable.
Wet the sponge with preferably distilled or tap water, and then place it into the tray. Plug the soldering iron line cord into the AC receptacle on the back, and then insert it into the holder. Make sure the On/Off switch is set to the Off position and the control knob at minimum. Plug the line cord of the SL-5 into a 120VAC receptacle. Turn the power switch On and the switch should illuminate. Set the temperature control knob midway. Allow the iron to heat up for a few minutes. Now set it to the desired temperature. See the chart for relative temperatures. Using the lowest power setting will protect sensitive devices.