The Dual-In-Line Package (DIP) integrated circuit was once cutting-edge technology. It displaced most discrete circuitry and led to a computer revolution. Today, the DIP has been replaced by smaller surface mount devices. However, the DIP form factor remains active in millions of vintage devices and is still used for niche applications.
This engineering brief explores the DIP sockets (integrated circuit sockets) that are often associated with the classic components. An example is the LM747 op amp shown in Figure 1. This dual-packaged 741 op amp mounted in a 14-pin socket, allowing quick replacement.
Figure 1: Image of an LM747 14-pin DIP op amp in a socket.
Tech Tip: A dot is often used to identify an IC’s indexing pin as shown in Figure 1. The socket’s associated indexing is implied two different ways as shown in Figure 2. Here we see the notch as identified by the green dot. We also see rounded corners associated with the red dots.
What is a DIP socket?
The DIP socket serves as an intermediary between the IC and the Printed Circuit Board (PCB):
- The socket’s pins are soldered directly to the PCB.
- The IC is held in the socket by spring tension.
An example is shown in Figure 2, where the springs for this Assmann WSW Components A 14-LC-TT are visible on the top of the socket. The solder tails are visible on the bottom of the socket.
Figure 2: Image of a 14-pin DIP socket showing the individual springs.
What are the advantages of a DIP socket?
The primary advantage of a socket is that it allows the IC to be quickly removed without soldering.
A better question is, why would we want to remove an IC in the first place.
Why are DIP sockets used?
There are several answers:
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Speed in restoring the equipment extending to the end user. While some consider this poor troubleshooting practice, simply replacing a suspect IC is often a fast and effective way to restore the equipment. At other times it is a recipe for disaster as the root cause was not identified requiring a follow up-repair.
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Speed in modifying equipment. For example, a guitar player may want to experiment with different op amps.
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Mitigate against variations in op amp performance. This would allow an OEM to quickly swap out component and otherwise match the IC to the circuit.
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Heat concerns with the PCB. The socket mitigates overheating and thermal shock of the components such as when the PCB is wave soldered. This is especially true for a novice hand-soldering an expensive component. The socket also mitigates against damaged (lifted pads) associated with manually desoldering a PCB.
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Supply chain problems are nothing new. A socketed IC allows the PCB to be populated and soldered while waiting for the IC(s) to arrive.
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Many ICs are susceptible to ElectroStatic Discharge (ESD). The socket allows easy replacement of the IC. It may also allow flexibility in manufacturing. For example, through-hole passives could be installed and soldered with the sensitive components installed later at a properly constructed ESD station.
Tech Tip: Many technicians have commented that a socket would be installed as part of a routine repair. If the IC was removed for any reason, a socket was installed. This way subsequent repairs could be quickly performed.
What are the disadvantages of a DIP socket?
While there are many advantages associated with the DIP socket, there are a few disadvantages.
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Added cost for equipment that never requires servicing. Here cost extends to the Bill of Material (BOM) and overhead to source and stock additional components.
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Oxidation and corrosion associated with the socket. The 14 additional spring pins as shown in Figure 1 are unlikely to be as reliable as a part directly soldered to the PCB. Then again, the pictured op amp was manufactured in the 18th week of 1990. Note the rust on the transformer to the left of the IC chances are high that corrosion has entered the socket.
What are the different types of DIP sockets and which is the best?
There is no singular “best” type of DIP socket. Instead, we are free to select the best available option based on cost, availability, and a host of performance metrics such as spring resistance, heat resistance, and susceptibility to oxidation.
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Gold plating is preferred for longevity and reduced susceptibility to corrosion. There are also a wide variety of alloys to consider as you balance cost against performance. An example is beryllium copper.
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Some designers prefer machined cups to open spring type connectors. As a rule, these add cost.
Tech Tip: As an instructor, I loved socketed ICs as there were so many ways to break the equipment. The bent and broken pin problems were easy to insert. Unfortunately, there is also a risk for self-induced problems.
To reduce the potential for bent and broken pins, we should use a tool such as shown in Figure 3. This Jonard S-340 is a classic socketed IC removal tool. When used with care the tool will keep the IC’s pins straight while it is removed from the socket.
Figure 3: Image of an IC extractor.
Tech Tip: There was a time when every engineer (programmer) knew about the Zero Insertion Force (ZIF) socket. These sockets typically included a lever to release spring tension allowing an IC to be removed with minimal risk of pin bending. The ZIF was typically associated with early microcontroller and EEPROM chips, where the expensive ZIF was installed in the device programmer. Today, it’s been largely replaced by flash memory, which allows In-Circuit Programming (ICP).
Should I use a socket for my IC?
Personally, I appreciate the technician’s advice. If you are going to desolder an IC, then add a socket. In my opinion, the benefits outweigh the risks as it is too easy to damage the PCB.
Finally, there is value in experimentation. Adding a socket allows you to try different things. The results aren’t as dynamic as substituting a 12AU7 for a 12AX7 vacuum tube, but it’s worth a try. You may even discover something in the process. Perhaps you’ll be met with something unexpected like an oscillation that you get to tame.
Attribution
I’d like to extend a thank you to all LinkedIn users who commented on my 14 May 2025 post featuring the Figure 1 image. Your passion brings clarity to these topics.
Parting thoughts
The DIP socket remains popular. In fact, at the time of this writing DigiKey has 12,419 active products.
Please add a picture in the comments section showing how you use the socket in your project.
Best wishes,
APDahlen
Related information
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About this author
Aaron Dahlen, LCDR USCG (Ret.), serves as an application engineer at DigiKey. He has a unique electronics and automation foundation built over a 27-year military career as a technician and engineer which was further enhanced by 12 years of teaching (interwoven). With an MSEE degree from Minnesota State University, Mankato, Dahlen has taught in an ABET-accredited EE program, served as the program coordinator for an EET program, and taught component-level repair to military electronics technicians. Dahlen has returned to his Northern Minnesota home and thoroughly enjoys researching and writing articles such as this.