This solution was developed for use in multiple test applications from inspection and failure analysis to engineering hand test. The flat-top socket convertible is a dedicated solution designed for the carrier/coupon boards with the pogo pin array specified to the packaged device. Compression force is made by the carrier/coupon board when it is screwed to the socket. The socket features dowel pins to align the coupon/carrier board to the test points. The FTSC socket base is a typical non-floating base but with the conversion kit, it transforms into a floating base.


The flat-top socket convertible design is similar to that of a traditional non-floating base socket except it has a removable floating piece and cover for use with packaged devices. The pogo pin array in the FTSC socket matches the packaged DUT, therefore the carrier/coupon boards must have a 1:1 matching footprint for use in this configuration. Screws keep the carrier/coupon board secured to the socket which allows 100% full access to the device and surrounding area making it ideal for inspection tools or test equipment.

Multi-Purpose Solution: Flat Top Socket Convertible

An original RTI solution developed to test packaged and WLCSP devices in two different forms. First as a stand-alone DUT and second as a DUT that has been reflowed onto a carrier/coupon board. FTSC sockets allow 100% full and unobstructed access to the surface of the DUT when mounted onto a carrier/coupon board. This is an ideal solution for failure analysis and reliability engineers using Solid Immersion Lens (SIL) inspection methods.

FTSC Features & Benefits: 

  • Single socket for all applications
  • Large cost savings at high pin counts
  • Test devices in traditional socket pocket using FA closed-top or sapphire window lids
  • Purchase the same socket for multiple facility locations with or without conversion kit for best quantity pricing

Benefits to Testing Device on Carrier/Coupon Boards:

  • Zero working distance; nothing is taller than the die
  • Used for short-working distance optics
  • No cover glass over the device; less distortion
  • Enables SIL lens use to the edge of the device
  • Stainless steel components ensure perfect flatness
  • Reduced stress on the device from pogo pin force
  • RTI can design carrier/coupon board down to 0.3mm pitch or match your design

Floating Base Conversion Kit

flat top socket exploded view of conversion kit

The FTSC floating base is more advanced than RTI’s standard floating base for IC test sockets. The conversion kit includes the floating piece and cover which are installed onto the socket base, converting it into an FTSC floating base. The floating piece allows ball devices to align to the recessed pin tips before compression force is made. The conversion kit is used only for the packaged device. RTI does offer device-dedicated lids such as open-top failure analysis lids, sapphire window lids, and clip-on removable lids.

SIL & Hand Test Applications

The FTSC socket is the ideal solution for failure analysis and reliability test engineers using SIL inspection methods requiring a lens to make direct contact with the die, and hand test applications.

  • Pitches down to 0.3mm.
  • 100% full and unobstructed access to package or die.
  • Floating base compatible with open-top FA lids, RTI’s sapphire window lids, and clip-on removable lids.
  • Carrier/coupon boards align test points to pogo pins using dowel pins in the socket base.
  • Useful in a variety of applications where hand tests and die-level inspections are required.
  • Relief cutouts in the socket base for full backside access to the device, or clearances for SMT components installed on a PCB.

More Resources

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    Bare Die & IC Test Sockets

    For BGA, QFN, WLCSP, PGA, QFP, TSSOP and other packaged device types.  Compatible with a variety of RTI’s socket lids based on your test application.

    PCB Module Test Sockets

    For small PCB sub-assemblies and multi-chip modules. Providing precise DUT alignment with relief cutouts for SMT components and more.

    PGA LGA image sensor socket

    Image Sensor Test Sockets

    For large-scale CMOS image sensors in ceramic packages to small cameras mounted to flex PCB’s.

    Cartridge Carriers & Test Sockets

    For small and fragile wafer-level devices that are prone to handling issues between test platforms.  Multi-site and single-site test socket configurations.

    Flat Top Socket Convertible for use with packaged devices, WLCSP

    FTSC Sockets

    Flat-top socket convertible sockets are a dedicated solution designed for the carrier/coupon boards with the pogo pin array specified to the packaged device.

    Universal Array Test Sockets

    For groups of BGA devices that share a common pitch but different physical dimensions. A device specific alignment plate justifies A1 to upper left corner.


    Robson Technologies, Inc. interconnects, fixtures and systems are carefully designed, manufactured, inspected, and individually tested prior to shipment. In the unlikely case you find a defect in materials or workmanship, we will promptly repair or replace the component.


    Do you need help finding a test solution? Get in touch with an RTI Engineer!



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    8:00am – 5:00pm PT