Soldering torches make 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. Among the types of soldering iron, these perhaps present the highest level of injury risk and thus require great caution during operation. Using soldering torches has various shortcomings as compared to various options. These include:
Higher levels of risk
Soldering torches usually burn fuel to produce a flame that in turn heats surfaces in readiness for soldering. This mechanism is often a recipe for disaster. First, the fuel used in the internal combustion chamber is usually highly flammable and could easily explode should anything go wrong. The flame used in soldering could potentially cause burns. The risk for this is higher than most other soldering alternatives.
High costs of maintenance and operation
Soldering torches are usually relatively cheap in the short run since this only involves the cost of purchase. However, operating a soldering torch requires periodic refilling of the fuel tank. The fuel in this case is soldering butane, not readily available. This, in addition to the high cost of spare parts makes soldering torches expensive in the long run as compared to alternatives such as soldering irons.
Once a soldering torch is ignited, there is little to no means of regulating the flame produced by the torch. Thus makes it very hard, sometimes impossible to solder on sensitive surfaces and components. This is a huge downside considering alternatives such as soldering irons have inbuilt temperature control means. The flame also burns in a relatively wide flame that might damage unintended parts while soldering.
Lead- Lead is a naturally occurring metal with a relatively low melting point. This implies that lead-based solder is very easy to work with due to its low liquidus. The lead-tin alloy for example has liquidus of a relatively low 370 degrees Fahrenheit. This made lead suitable for what is known as soft soldering. Lead is often used with tin to improve the tensile strength, shear strength and wetting of the solder.
Lead- Lead can also be used to describe a piece of wire or strip of metal running from one or multiple ends of a component to the surface of a printed circuit board. Leads vary in type and are used to transfer electric currents, support components and act as heat sinks for heat produced by the components on the PCB.
Lead poisoning- This is a significant health hazard present in the use of solder. When lead is heated, it turns to lead oxide and through naturally occurring can cause serious health problems. Other methods such as wielding and adhesive binding do not make use of lead and are therefore safer as compared to soldering. Long term lead poisoning effects take place once the lead has accumulated in the body thus producing free radicals.
Lifted pad- Lifted pads are rare but possible occurrences. It basically involves pad lifting from the printed circuit board once soldered. This does not happen with techniques such as the through-hole technique but is very possible with surface-mount techniques. It represents one of the hardest problems to solve in soldering since a lifted often disengages the copper track from the circuit board.
Lead-free solder- Lead free solder is composed of alloys that do not contain lead. Lead free solder has become particularly common especially with the banning of lead use for plumbing purposes. Examples of lead free solder include tin-silver-copper and tin-copper alloys.
Bridge fill- This is a step in desoldering of surface-mounted components and is essentially part of what is known as thermal enhancement. Under this, all component leads are soldered together, what is known as the fill and then reflow happens simultaneously and rapidly to all the soldered joints.
Bake-out- This is basically exposing all components on a printed circuit board to extremely high temperatures before soldering or sealing the joints or the components onto the board. This is usually done to remove unwanted gasses and excess humidity from the board.
Ball grid array- This is a type of surface-mount technology where the components do not have leads. Unlike conventional surface mounting, the components have terminations made of solder below them that serve as leads. The specific term for this technology is controlled collapse soldering. The solder columns replace component leads.
Base material- Also known as substrate, this is the material that is layered onto a printed circuit board onto which electrical tracks are then laid. The base material is in most cases non metallic to prevent movement of current through unintended paths. The exact components of the base material vary from one manufacturer to the other.
Bifurcated solder terminal- This is basically a regular soldering iron terminal but with the addition of a slot through which wires can be passed through or placed before soldering. The number of components that can be placed on the terminal varied with the type of terminal.
BQFP- This stands for a bumpered quad flat-pack. In soldering, this is a term for packages in SMT that has leads on all four sides and a plastic chip type of carrier. The bumpered term represents the bumpers on the carrier’s four sides that protect the SMT component’s four leads.
Celsius- This is among the many temperature scales used in soldering. Under the Celsius scale, the freezing point of regular water is 0 degrees and its boiling point is 100 degrees. However, these numbers are assumed to work perfectly at sea level and changes in pressure due to changes in altitude could affect the results.
CCGA- The term stands for ceramic column grid array. This generally represents a type of SMT technology where a PCB uses a ceramic body and components without leads. In place of leads, the components are held onto the board by what is known as bottom side terminations. These are basically balls of solder that are normally reflowed using the previously discussed controlled collapse soldering.
CGA- Stands for ceramic grid array. This generally represents a type of SMT technology where a PCB uses a ceramic body and components without leads. In place of leads, the components are held onto the board by what is known as bottom side terminations. These are basically balls of solder that are normally reflowed using the previously discussed controlled collapse soldering. It’s a term commonly interchangeable with ceramic column grid array.
Certification- In soldering, this is the verification given to a person or body to ascertain that they have undergone sufficient training or testing and the required levels of marks, proficiency, values or grade attained.
Chip component- This is a term used to describe a normally passive PCB component such as a resistor or capacitor. The components are usually almost entirely made of ceramic material and have metallic leads at both ends. However, if fixed using methods such as CCGA, the components will normally have solder columns in place of the conventional component leads. The component leads often provide the sodlerable contact for fixing on PCBs.