IC test socket selection guide
An IC test socket holds a packaged device against a test or burn-in board without soldering, so the same board can test many parts. Picking the right one comes down to the package footprint, the lead pitch, how the lid opens and what the socket will be used for: bench validation, programming, final test or burn-in.
This guide covers the choices buyers make most often and lists the socket models available through MST from Plastronics (Smiths Interconnect), Enplas and Elnec.
Start with the package, not the socket
- Package family and pin count, for example QFN32, QFP64 or SOIC8.
- Body size in millimetres and lead pitch (0.4 mm, 0.5 mm, 1.27 mm and so on).
- Exposed pad: QFN sockets usually need a center ground contact for the thermal pad.
- The JEDEC outline or the device datasheet drawing, so the socket maker can confirm the footprint.
Lid style: clamshell or open-top
A lidded (clamshell) socket closes a hinged lid over the device and is common for manual bench work and burn-in. An open-top socket is loaded from above by pressing the frame, which suits frequent manual swaps and automated handling. Smiths Interconnect offers both lidded and open-top QN-series sockets for QFN packages up to 10 mm, and lidded sockets for 10 mm to 16 mm packages.
Contact type and use case
- Spring-probe (pogo) contacts: the Plastronics QN-series QFN sockets listed below use spring-probe contacts.
- Pinch or tweezer contacts in open-top QFP sockets, such as the Enplas OTQ series, grip the gull-wing leads.
- ZIF programming adapters, such as the Elnec DIL8W/SOIC8, convert a surface-mount package to a DIL plug for device programmers.
- Burn-in: confirm the temperature range and cycle life with the socket maker before ordering for long burn-in runs.
Test sockets available through MST
| Package | Body | Pitch | Manufacturer | Part number | Style |
|---|---|---|---|---|---|
| QFN16 | 3 × 3 mm | 0.5 mm | Plastronics (Smiths Interconnect) | 16QN50S23030 | Lidded clamshell, spring probe |
| QFN24 | 4 × 4 mm | 0.5 mm | Plastronics (Smiths Interconnect) | 24QN50S14040 | Lidded clamshell, spring probe |
| QFN32 | 5 × 5 mm | 0.5 mm | Plastronics (Smiths Interconnect) | 32QN50S15050 | Lidded clamshell, spring probe |
| QFN48 | 6 × 6 mm | 0.4 mm | Plastronics (Smiths Interconnect) | 48QN40TS16060 | Lidded clamshell, spring probe |
| QFN48 | 7 × 7 mm | 0.5 mm | Plastronics (Smiths Interconnect) | 48QN50S17070 | Lidded clamshell, spring probe |
| QFN64 | 9 × 9 mm | 0.5 mm | Plastronics (Smiths Interconnect) | 64QN50S19090 | Lidded clamshell, spring probe |
| QFP64 (LQFP/TQFP) | 10 × 10 mm | 0.5 mm | Enplas | OTQ-64-0.5-01 | Open-top, pinch contact |
| SOIC8 150 mil | 3.9 mm | 1.27 mm | Elnec | 70-0901 (DIL8W/SOIC8 ZIF 150mil) | ZIF programming adapter |
Confirm the full outline drawing against your device before ordering; the same pin count can come in several body sizes.
What to send with a socket RFQ
- Device package drawing or JEDEC outline, pin count, body size and pitch.
- Use case: bench test, programming, final test or burn-in, and the temperature range.
- Board interface: through-hole, surface-mount or an existing board footprint you must match.
- Quantity and target date.
Frequently asked questions
What is the difference between a test socket and a burn-in socket?
Both hold a device without soldering. A burn-in socket is built for long runs at elevated temperature on a burn-in board, while a test socket is used for functional or parametric test and bench validation. Many lidded QFN sockets are offered for both uses; confirm the rated temperature and cycle life for your run.
Which pitches do Plastronics QN-series QFN sockets cover?
Smiths Interconnect lists the QN series in 0.40, 0.50, 0.65, 0.80 and 1.00 mm pitches, with custom pitches down to 0.35 mm and a center ground pin as standard.
Can I get a socket for a package that is not listed?
Yes. Smiths Interconnect states QN-series sockets exist for more than 80 JEDEC standard footprints. Send the package drawing and MST will check availability and lead time with the manufacturer.
Does MST manufacture test sockets?
No. MST is a distributor. Sockets are made by the manufacturers named on each product page, and MST sources and quotes them.
Need a socket for your package?
Send the package drawing, pitch and use case. MST checks the matching socket with the manufacturer and replies with price and lead time.
Request a socket quoteRelated pages
Sources
Values are taken from the manufacturer documents above, checked 2026-10-22. Specifications can change; confirm against the current datasheet before ordering. MST is a distributor; products are made by the manufacturers named.