Ic holders (dil sockets)

ICs (chips) are easily damaged by heat when soldering and their short pins cannot be protected with a heat sink. Instead we use an IC holder, strictly called a DIL socket (DIL = Dual In-Line), which can be safely soldered onto the circuit board. The IC is pushed into the holder when all soldering (впаивание) is complete.

IC holders are only needed when soldering so they are not used on breadboards.

Commercially produced circuit boards often have ICs soldered directly to the board without an IC holder, usually this is done by a machine which is able to work very quickly. Please don't attempt to do this yourself because you are likely to destroy the IC and it will be difficult to remove without damage by de-soldering.

Removing an IC from its holder

If you need to remove an IC it can be gently prised out of the holder with a small flat-blade screwdriver. Carefully lever up each end by inserting the screwdriver blade between the IC and its holder and gently twisting the screwdriver. Take care to start lifting at both ends before you attempt to remove the IC, otherwise you will bend and possibly break the pins.

Static precautions

Antistatic bags for ICs

Many ICs are static sensitive and can be damaged when you touch them because your body may have become charged with static electricity, from your clothes for example. Static sensitive ICs will be supplied in antistatic packaging with a warning label and they should be left in this packaging until you are ready to use them.

It is usually adequate to earth your hands by touching a metal water pipe or window frame before handling the IC but for the more sensitive (and expensive!) ICs special equipment is available, including earthed wrist straps and earthed work surfaces. You can make an earthed work surface with a sheet of aluminium kitchen foil and using a crocodile clip to connect the foil to a metal water pipe or window frame with a 10k  resistor in series. 

19. Read the text again and complete the sentences.

1. Many ICs are static sensitive and can be damaged when you … .

2. Integrated Circuits are usually called … .

3. … link the chip to the pins.

4. It is usually adequate to earth your hands by … .

5. Commercially produced circuit boards often have … .

6. …, otherwise you will bend and possibly break the pins.

7. You can make an earthed work surface with … .

8. The IC is pushed into the holder when … .

9. … because your body may have become charged with static electricity.\

10. … which can be safely soldered onto the circuit board.

20. Match the terms in Table a with their definitions in Table b.

A.

1. chip

2. circuit

3. pin

4. solder

5. screwdriver

B.

1. the complete circle that an electric current travels.

2. a soft metal, usually a mixture of lead and tin, which can be melted and used to join two metal surfaces, wires etc

3. a tool with a narrow blade at one end that you use for turning screws.

4. a small piece of silicon that has a set of complicated electrical connections on it and is used to store and process information in computers.

5. one of the pieces of metal that sticks out of an electric plug.