IC Socket Technical Information

1. What is IC socket?

IC socket is a tool that connects an IC and a printed circuit board electrically to verify the electrical characteristics and to evaluate the reliability of the IC . IC socket can be used for such reliability test repeatedly by inserting and removing multiple ICs.

 

 

Generally, IC socket can be divided into two categories. One is for commodity PKGs such as SOP and DIP. For these devices, IC sockets are inexpensive, and have easy access so as to try and evaluate ICs at room temperature, for example.

The other is for custom PKGs that are in the IC manufacturing process. For these devices, some IC sockets are used in harsh test environments for screening ICs.
Also, the custom IC sockets used in the IC manufacturing process can be divided into two types (1) Burn-in (BI) socket: to screen initial defects of ICs by applying voltage or signal in a high-temperature stress environment (2) Test sockets: to inspect the electrical characteristics of ICs or perform final test to see if they meet the specifications. In this way, there are various types of IC sockets depending on the purpose and environment in which they are used.

For more detailed explanations of Burn-in socket and Test socket, please see below.

Burn-in socket

Test socket

 

 

2. Concerns in the IC manufacturing process and solutions

　While general-purpose IC sockets will work by just putting commodity PKGs inside, custom IC sockets that are used in the IC manufacturing process have a variety of concerns.
Let’s see the details of such concerns and tips to solve them.

① Thermal runaway

　Since thermal runaway likely occurs during BI test, BI sockets need to be designed based on thermal simulation data so that the sockets will have optimized Heat sink, Heat pipe or Individual temperature control system.

② High current

High current also likely causes ICs thermal runaway. Thermal control solutions such as Heat sink or Multiple contact pins that dissipate the heat will be required.

③ High frequency

Since ICs such as CPUs and GPUs operate at high speeds, test sockets for inspecting the electrical characteristics of such ICs are also required to support high frequencies. It is necessary to select a contact pin that minimizes insertion loss and return loss.

④ Durability

IC sockets used in the IC manufacturing process are particularly prone to have plating peeling and solder transfer on the tip of the contact pins. It is necessary to apply an appropriate plating and coating to contact pin tip depending on the test environment.

⑤ Operability

To keep reliable contact between IC and contact pin, considerable pressing force is required. That makes it hard to insert and remove the IC. IC sockets with bail mechanism can obtain sufficient pressing force easily.

⑥ Auto loading

　In the mass production process, ICs are inserted into IC sockets by auto loader. IC sockets need to be compatible with the auto loader.

⑦ Contact stability

IC sockets used in the IC manufacturing process have to withstand electrical and thermal stress while measuring electrical characteristics. It is necessary to apply an appropriate plating and modifry the shape of pin tip depending on the test environment.

⑧ Foreign matterial

Since sensor ICs such as CMOS image sensor are tested not only electrically, but also physically, the inspection cannot be completed if foreign matterial lies on the sensor part. IC socket that can prevent foreign matterial from entering is required.

⑨ Versatility

Custom IC sockets can take extra cost. IC socket with the combination of molded frame and custom module for different thicknesses of PKGs can realize flexibility

⑩ High pin count

As IC’s function increases, the pitches are becoming finer and the number of pins is increasing. As a result, it is necessary to select a contact pin that is inexpensive and meets the required specifications.

⑪ Cost

Custom IC sockets can take extra cost. IC socket with the combination of molded frame and molded module can realize low cost.

 

 

3. To select the best IC socket

When determining the specifications of custom IC socket for the manufacturing process, it is necessary to clarify what to test and the testing environment. At the same time, it is important to understand what kind of solutions IC socket vendors are developing.

Enplas Semiconductor Peripherals, the owner of this IC Socket Solutions.com, introduces various solutions for custom sockets along with their features, so please check below.

 

List of the solutions we offer