In the ever-evolving world of semiconductor testing, Robson Technologies, Inc. (RTI) has been at the forefront of providing innovative solutions for over three decades. As the demand for faster, more efficient, and reliable testing methods continues to grow, RTI offers a range of solutions designed to meet the unique needs of the industry. Two key innovations are RTI’s Multi-Site test sockets and Cartridge Carriers, each with its own set of advantages and applications.

In this blog post, we will explore the differences and benefits of Multi-Site Sockets and Cartridge Carriers, shedding light on how their fundamentally similar yet unique designs contribute to improved efficiency across the semiconductor testing landscape.

Multi-Site Sockets: Enhancing Throughput and Efficiency

Multi-Site Sockets are designed to optimize semiconductor testing efficiency. They achieve this by testing multiple semiconductor devices at once in a single socket body, which is useful for burn-in and mid-volume hand testing of packaged ICs (Integrated Circuits) and modules.

Here’s what makes Multi-Site Sockets stand out:

  • Cost Efficiency: The ability to test multiple devices simultaneously translates to lower cost per-site testing. This is especially important for cost-sensitive industries like consumer electronics, where high-volume production is the norm.

  • Compact Design: RTI’s Multi-site sockets are designed to be space efficient. They occupy minimal space per test site on the test board, allowing semiconductor manufacturers to optimize their testing resources.

  • Operation with Pick and Place: Automated handlers that manage individual device loading and removal can be used to streamline DUT (Devices Under Test) management between test cycles, something that isn’t available with cartridge carriers.

Cartridge Carriers: Versatile Solutions for Advanced Applications

Cartridge Carriers also offer multi-site parallel testing of devices but aren’t built like traditional multi-site test sockets.  They are designed to eliminate the process of loading and unloading individual devices from the test socket between test cycles.  The cartridge carriers provide improved device management in semiconductor testing and are a versatile solution when used with different sockets across a variety of test methods. They are particularly useful for testing batches of small or fragile WLCSP and sensor devices that are prone to damage or loss typically experienced during the device loading process.

Let’s delve into their unique advantages:

  • Reduce Device Handling Errors: Cartridge Carriers eliminate the process of inserting and removing individual DUTs from test sockets at each stage of test. This greatly reduces the chance to damage or lose devices between test cycles and helps track the DUTs across various test beds without the need to handle the DUT’s in between.

  • Universal Designs: The multisite pin blocks and sockets used with cartridge carriers can have universal pin arrays for compatibility with array-based devices of the same pitch but different pin counts.

  • Reduced Downtime: Downtime is minimized with rapid loading and removal of cartridge carriers when compared to manual loading/removal of DUTS from traditional test sockets. Up to 20 devices can be loaded in a cartridge carrier in the same amount of time as manually loading one device into a multi-site test socket. This is particularly beneficial for semiconductor testing environments where uptime is a top priority.

Choosing the Right Solution

The choice between Multi-Site Sockets and Cartridge Carriers ultimately depends on the characteristics of the DUT and the comprehensive test programs employed by the testing facility.

Here are some factors to consider:

Multi-Site SocketsCartridge Carriers
Device TypesAny type of packaged IC, discrete component, and some modules. DUTs usually >3mm in size.Ideal for sub-2mm WLCSP, MEMS, and bumped die devices that are easily lost or damaged when handled.
Socket LoadingDevices are individually loaded and removed from each site in the test socket between test cycles and across tester platforms.Devices are pre-loaded into a multi-site carrier that is then mounted and removed from the test socket between test cycles and across tester platforms.
Socket MountingThe DUT board must seat and route signals from every site on the multi-site test socket, regardless if only one site is being tested.The DUT board can also mount and route signals from a single site test socket which aligns to and contacts each individual test site on the multi-site cartridge carrier.
Device HandlingDevices are handled every time the socket is loaded and unloaded between test cycles.Devices are only handled when loading or unloading the cartridge carrier, not between each test cycle.
CompressionA clip-on or screw-down lid applies downward force directly on each DUT, pushing the DUT against theThe top plate of the cartridge carrier assembly provides resistance when the cartridge is mounted to the pogo pin test socket. Spring pins in the test socket provide force, carrier lid provides resistance.
Electrical ContactsSpring pins, elastomers, and similar.Spring pins only.
Socket FootprintsTest sockets with fully customizable footprints and test site positioning for each DUT board.Test sockets for every test board must be made compatible with the cartridge footprint first.
Number of SitesThe contact footprint at each test site on the socket must match the DUT footprint. Each test site can be drilled for a unique footprint.Contact footprint at each site on the socket can be a universal array. Positioning of drill holes on the cartridge must match the DUT footprint and mask unused pins.


RTI offers a comprehensive suite of solutions to address the diverse needs of semiconductor testing facilities. Whether you require increased throughput and cost efficiency through Multi-Site Sockets or the improved device management across various test platforms provided by Cartridge Carriers, our innovative products are designed to optimize your testing processes and keep your long-term semiconductor testing operations working at peak efficiency.

By carefully considering your testing requirements and weighing the benefits of each solution, you can make an informed decision that suits your business objectives and operational needs.

To further discuss your needs, please contact us.