solder-starved joint

Soldering Terms III

Substrate- This is the base material that gives a PCB its thickness. For most printed circuit boards, this is usually fiberglass or kapton. The substrate, often known as FR4, gives the PCBs the rigidity required to hold several components in place. The thickness and weight of the substrate will vary from one manufacturer to the other.

Solder-starved joint- In soldering, a solder-starved joint is the point of a bond formed by molten solder that did not receive as much solder as required. Solder starved joints can be caused by a wide range of factors including incorrect soldering temperatures, poor contact between the solder and iron tip and use of poor quality solder. A solder-starved joint often develops cracks with time, forms poor bonding of components and is thus generally unreliable as a contact point especially in soldered electrical components.

Solder- Solder is the metal alloy commonly used to join work-pieces that include sheets of metal, wires, plumbing and other elements common in soldering. The alloy is designed to have a melting point that is lower than that of the components it joins. Without this characteristic, the work-pieces would probably be damaged by the solder or even before the solder effectively binds them.

Soldering- This is the process by which solder is heated using an external heat source and melts to flow into joints and make bonds between metals.

Soldering iron- It is in essence a small, often hand-held tool that could be power or gas operated depending on a variety of factors that melts solder from a source of heat to join various elements known as work-pieces. A soldering iron is made of four components, the power cord –for electric soldering irons- , the tip, thermostat control and the grip. There are various types and configurations of soldering irons.

solder cradle

Soldering Materials

Soldering torch- A soldering torch makes use of an inbuilt or external tank of gas, in most cases butane to produce heat. The most commonly-used gases include acetylene, propane and butane. These produce short flames of heat as is characteristic with the combustion of the aforementioned gases.

Soldering gun- A soldering gun is in essence an electrically-operated soldering iron shaped like a gun and uses the trigger to transfer and control heat transfer. A soldering gun is usually used in situations where the soldering needed requires more heat than can be supplied by a soldering iron. Soldering guns have a wattage ranging from 100 to 220 watts of power. However, this high wattage also implies that soldering guns, unlike irons cannot be used for soldering on circuit boards with small and sensitive components.

Soldering station- A soldering station is the all-inclusive package for your household soldering. It contains the basic tools for soldering such as a soldering iron, soldering base, brass sponges, interchangeable tips and perhaps a soldering stand.

Soldering base- A soldering base is in its most basic configuration a box that has dials or buttons used to control the temperature for a soldering iron. Digital soldering iron bases have buttons and a display that shows the current settings while analogue bases have knobs and dials used to adjust the heat.

Soldering cradle- A soldering cradle is a small tool on which a soldering iron is usually placed on to avoid rolling off the workspace. Soldering cradles come in a variety of designs and components within them. The most common are the basic, brass sponge and regular sponge soldering cradle. Each of these has its advantages and shortcomings with the brass sponge soldering cradle being the best of all.

solder mask

Soldering Guide II

Solder balls- These are small balls of solder that form randomly in the surface of a printed circuit board. The process of formation is known as solder balling. There are various reasons that lead to the formation of solder balls. These include poor resist coatings, gassing of flux, turbulence, spitting, poor workmanship and wrong preheating.

Solder beads- Solder beads are related to solder balls. However a solder bead refers to a group of solder balls that form closely together and thus resemble a bead. Solder beads often occur close to the components that were being soldered. However, solder paste plays the greatest part in the formation of solder beads unlike solder balls where the solder plays the greatest part.

Solder bridge- A solder bridge is an unintended connection between two components on a printed circuit board formed through the excess flow of solder paste between components. Solder bridges can conduct electricity and are thus defects in soldering.

Solder mask- Solder mask is basically the layer above the copper layer and gives most PCBs their green or red coloring. The solder mask serves to protect the components and electrical points from coming into accidental contact through solder. Basically, solder will not stick on the solder mask and can therefore not for electrical conducting solder balls or beds and link two points. Solder mask may cover most of the PCB depending on the type and number of components on the board.

Silk screen- This is the layer that comes on top of the solder mask. Basically, the silk screen is used for lettering and numbering components on the circuit board. Silk screen comes in a variety of colors including white, yellow, blue and orange. However, white is the prevailing silkscreen color for use in printed circuit boards.