IC Socket -Selection Guide It is observed that for many industrial users it is very difficult to choose proper IC Sockets, this article will help you to choose correct IC Sockets for your use.

2. 1. What is an IC Socket?
2. Applications for IC Sockets:
3. Contact Types:
4. Insulators
5. Insertion Force
6. Height Above Board
7. Tail Length
8. Plating
9. Popular sizes in DIP
10.Types Of Packages
11.Mounting on PCB Options
12.Mounting Direction on PCB
13.Packaging

3. • An IC (integrated circuit) socket, is used to connect an
integrated circuit to PCB.
Key roles are as follows :
• Placeholder for IC chips
• Safe removal and insertion of IC chips
• Protection of ic chips from heat due to soldering and
desoldering.

4. • Providing safe removal and insertion of IC chips
• Prototyping new circuits
• Field upgradability
• Connecting two boards

5. Contact Types
Machined Pins
Two Piece Construction
Sleeve
Made of Brass
Clip
Made of Beryllium Copper
Stamped Pins
One Piece Construction
Wiping Connector Blade
Made of
Brass or Phosphor Bronze

6. • Shell or sleeve is made of brass alloy 360 ½ hard for
strength, conductive, and thermal properties.
• Press-fit assembled inside each shell is a highly reliable,
four-finger beryllium copper contact clip, which scores
the mating device lead, forming a gas-tight electrical
and mechanical connection.
• For high-temperature applications of more than 150°C,
an alternative beryllium nickel alloy is available.
• Multi-finger contact clips are superior to stamped pin
wiping connector blades because they provide multiple
points of contact to the mating pin, resulting in
providing better power and force distribution.
• Two-piece receptacle construction (shell and contact
clip) allows for cost-efficient plating combinations.
• Receptacle shells can be plated with tin for solderability.
• Contact clips can be gold-plated for optimum
conductivity.

7. • Socket insulators are made from PBT for
through hole soldering.
• If sockets are going to be soldered in
mixed processing of through hole as well
as SMT, high-temperature thermoplastics
suitable for reflow soldering temperatures
is used.
• Normal insertion force for sockets
are Maximum insertion force 270
grams and Minimum withdrawal
force is 90 grams.
• In PGA Sockets one can substitute
normal clips with low force clips
and forces will be 90 grams and 25
grams respectively.

8. • For normal application height above
board is 4.45 mm.
• Height in various standard dimensions up
to 30 mm is normally available.
• Height as low as 2,41 mm is possible.
• Normally tail length for 1.6 mm board is 2.92
mm.
• In multi-layer boards longer tail lengths to
accommodate boards up to 7.10mm thickness
is normally available.

9. Plating
Sleeve
Tin Plated
Clip
Normal
Environment
Tin Plated Flash Gold
Harsh
Environment
Gold Plated
0.25 micron
gold thickness
0.75 micron
gold thickness
Note : Both sleeves and clips normally have nickel undercoat to prevent zinc
from migrating to top which can create intermetallic compounds making
sockets difficult to solder.

10. • Standard DIP Sockets are normally available in following sizes :
Centre Dist. No. of Pins
5.08mm (0.200") 10
7.62mm (0.300") 04 06 08 10 12 14 16 18 20 22 24 28 32
10.16mm (0.400") 20 22 24 28 32
15.24mm (0.600") 10 18 24 28 32 36 40 42 48 50 52 64
22.86mm (0.900") 50 52 64

11. • In addition to standard DIP sockets there are other packages
such as Shrink DIP.
• In addition, Single In Line Strips in single row and dual rows are
available for mounting odd sizes of IC’s.
• Other packages for which sockets are used are TO packages,
Fuses Relays (Partially filled), sensors.

12. • For manual insertion of sockets Thermocole (EP sheets) is
recommended.
• For automatic insertion of sockets packing in Tubes is
required.
• Normal method is through hole.
• SMT sockets are available for SMT boards
• Normally Sockets are mounted horizontally on PCB.
• In case of Displays 90 degree bent sockets can make it easy
to see displays.

13. • Author Nalin P. Sheth, MBA Harvard, is Managing Director of
Champion Electronics Pvt. Ltd., Pune, India.
• Champion Electronics is serving electronics industry all over the
world from 1975.
• Contact Details :
• Email : sales@champelec.com
• Ph: +91-8928502180.
• Website : www.champelec.com