As modern CSP devices continue to shrink in size, the difficulty in handling these devices between tests becomes a greater challenge. Constantly loading and unloading test sockets with such unwieldy small devices increases the risk of inventory loss due to product mishandling. RTI developed this Cartridge Carrier and socketing solution for device manufacturers that need to test volumes of very small WLCSP, MEMs Sensors, and packaged IC devices across a variety of test platforms.
See the Cartridge Carrier and Sockets Brochure.
Device-specific cartridge carriers are designed to protect small and fragile DUTs both during tests and in between test sequences. Cartridge carriers themselves do not include any pogo pins or electrical contacts and must be used with compatible test sockets to complete the interface between the DUT and PCB. Cartridges are typically 80mm x 20mm x 3.3mm assembled. Custom cartridge footprints and device arrays are available.
The carrier base (maroon) is precision machined with a series of pockets, each drilled to match the footprint and dimensions of the DUTs. A shallow groove is milled across each pocket to provide additional airflow across each DUT during the test. Devices are loaded into each pocket with balls/pads/leads aligned to the drilled holes that will later be probed by pogo pins in the test socket. Cartridges can accept devices with 0.3mm pitch and greater.
The cartridge lid (blue) fully retains the devices in the cartridge, preventing them from moving during transit and test. Standoffs at each test site are machined to meet the depth of the package. They apply no pressure against the DUT and act as a hard stop when pogo pins apply contact force. Small holes at each test site allow for access to the top of the DUT during the test or for forced air temperature testing.
Cartridge Carrier Design Features:
- Drilled for very fine pitch devices >= 0.3mm
- Universal drilled arrays justify A1 to the top left corner
- Number of test sites per cartridge based on DUT size and pin count
- Consistent alignment features for use with different socket designs
- Low-magnetic permeability materials available for lid/cartridge/hardware
- ESD sensitive materials available for lid/cartridge/hardware
- Provides airflow across the devices at each site
- Provides fine ball alignment across individual sites
- Can be drilled for arrays larger than the device size and made universal
Cartridge Test Sockets
Single and multi-site cartridge sockets align a cartridge carrier to exposed pogo pins and provide electrical contact to one or more test sites simultaneously. They are mounted to the PCB with 4 screws and can be customized in a variety of ways to meet your PCB layout and test requirements. Pogo pins provide the contact force against the DUT required for the test. Very fine pitch, low force, low-magnetic permeability pogo pins, and materials are available for sensitive DUT’s.
Single Site Clamshell Cartridge Sockets
Single Site Socket Design Features
- Single-site universal array test sockets accept cartridges with various array sizes of the same pitch
- Precise alignment of each test site to pin array
- Test socket adds no pressure to the DUT except what is applied by the pin force
- Designed for fine pitch and low pin count devices
These small footprint clamshell test sockets provide electrical contact to any single DUT loaded in a cartridge carrier. Alignment posts positioned close to the pogo pins match alignment holes corresponding to the test site on the cartridge carrier for fine vertical alignment. Single site sockets are useful for quickly retesting a suspect device that may have erroneously failed during a multi-site test.
Multi-Site Clamshell Cartridge Sockets
Multi-Site Socket Features
- Universal arrays justify A1 to the top left corner
- Multi-Site universal array pogo pin block accepts cartridges with various array sizes of the same pitch
- Cartridge allows for airflow across devices at each site
- Cartridge provides ball alignment across individual sites
With a footprint that nearly matches the cartridge carrier itself, these clamshell test sockets provide electrical contact to two or more DUTs loaded in a cartridge carrier. Keyed alignment posts positioned at the long edges of the socket align the cartridge to the arrays of pogo pins and assist in vertical loading. Multi-site clamshell sockets can save valuable time in high-volume testing.
Multi-Site Cartridge Sockets
Unlike the clamshell cartridge sockets, these low-profile test sockets share a footprint with the cartridge carriers and occupy less space immediately around the test sites. cartridge carriers are mounted directly to the socket with 4 screws. With no clamshell lid to obstruct the cartridge lid, the surface of the DUT sits much closer to the surface of the assembly. Protective covers prevent debris from collecting on pogo pins when not in use with a cartridge carrier.