58212 CLED Mapping

Chroma manufactures the 58212 CLED mapping prober.^[1][2]

The Chroma 58212 CLED is a mapping prober used for device testing and probing.^[1][2]

Probing systems use a precision motion stage to align a substrate beneath a probe head. The probe head holds a set of contacts that match the bonding pad pattern of the die under test. The prober lowers the contacts onto the die, applies test signals, and measures the device response.

In a mapping prober, the stage then moves to the next die and repeats the sequence automatically. Each measured die is assigned a pass or fail category, and the position of every result is stored in a substrate map. The map is the output that downstream sorting equipment uses to identify good die.

For light-emitting diode products, the prober is positioned after epitaxial growth and device processing and before die singulation. The map generated at the probe step tells the die sorter which die to collect and which to discard. Back-end assembly then uses only the die that were marked as known good.

A CLED mapping prober is intended for probing light-emitting diode die at the wafer level. The equipment supports production testing in which each die is electrically and optically evaluated before it is singulated. Typical measurements include basic electrical integrity and light-output behavior used for sorting die into performance groups.

The mapping function is especially useful for display and LED applications, where a single wafer contains many individual light-emitting devices. The resulting map allows dead or weak emitters to be separated from good die. Sorting and binning rely on the map to place each die into the correct performance and wavelength category.