INTER CONNECTION METHODS AND SOLDERING PRACTICE

AIM:

            To study the different  inter connection methods using electronic circuits.

COMPONENTS AND EQUIPMENTS REQUIRED

Bread board, connectors, crimping tool, soldering iron, PCB, solder flux

THEORY

a)Breadboard

A breadboard is a construction base for prototyping of electronics. It is a rectangular plastic board with a bunch of tiny holes in it. These holes let you easily insert electronic components to prototype (meaning to build and test an early version of) an electronic circuit.Because the solder less breadboard does not require soldering, it is reusable. This makes it easy to use for creating temporary prototypes and experimenting with circuit design. For this reason, solder less breadboards are also extremely popular with students and in technological education.

b) CRIMP CONNECTION 

A crimp connection is achieved with a type of solderless electrical connector. Simple crimp connectors are typically used to terminate stranded wire. Specialised crimp connectors are also used, for example as signal connectors on coaxial cables in applications at high radio frequencies (VHF, UHF).

c) SOLDERING

Soldering is a skill that requires both knowledge and practice. Soldering is a method of joining metal parts using a filler metal of low melting point (solder).  Purpose of soldering is  (i) Good Electrical Connections ii) Strong Mechanical Connections. Soldering Iron is used to melt the solder and to make the joint of the metal parts. The reverse process of soldering is called de-soldering.

i)SOLDERING IRON

To make good connection you have to heat the junction somewhat above the melting temperature of solder this is the job of the soldering iron. • Soldering iron comes in different sizes. • It is rated in terms of wattage (5W to 100W). • Thicker connection such as connectors requires more heat from soldering iron so we need higher wattage soldering iron. • Lighter connections like IC pins requires less heat so requires only less wattage irons.

SOLDER 

Solder is a metal or metallic alloy used, when melted,Ø to join metallic surfaces together. The most common alloy is some combination of tin and lead.  Certain special applications may require SilverØ Solder.  Solder can be selected considering followingØ  Low melting temperatureØ  Narrow or No soft regionØ  60/40 is the most common for electronic soldering.Ø  Solder wire available in different diameters, largerØ diameter required for soldering connectors, small diameters is sufficient for PCB soldering.

DESOLDERING TECHNIQUES

Desoldering is done to remove the solder from a joint, because of replacement for a faulty component or for fixing a dry joint.

DESOLDERING PUMP 

The usual way is to use a desoldering pump which works like a small spring-loadedØ pump, only in reverse (More demanding users using CMOS devices might need a pump which is ESD safe.)  A spring-loaded plunger is released at the push of a button and the molten solder is thenØ drawn up into the pump. It may take one or two attempts to clean up a joint this way, but a small desoldering pump is an invaluable tool especially for PCB work.

                        DESOLDERING WICK 

An excellent alternative to a pump is to use desoldering wick which are packaged inØ small dispenser reels.  This product is a specially treated fine copper braid which draws molten solder up intoØ the braid where it solidifies.  The best way is to use the tip of the hot iron to press a short length of braid down ontoØ the joint to be de-soldered.  The iron will subsequently melt the solder, which will be drawn up into the braid. TakeØ extreme care to ensure that you don't allow the solder to cool with the braid adhering to the work, or you run the risk of damaging PCB copper tracks when you attempt to pull the braid off the joint.

RESULT

Studied the various interconnection methods.