CROSS SECTIONING SERVICE
Fiber Optic Connector Cross Sectioning and Analysis Service
Fiber Optic Center offers a unique cross-sectioning service to identify and isolate problems related to fiber optic terminations that would otherwise be invisible. This process starts by performing a metallographic analysis of a fiber optic connector requiring several hours of vacuum desiccation followed by vacuum mounting of the samples with a slow cure, low expansion mounting epoxy. These encapsulated samples are then manually polished, maintaining precise flatness, depth and co planarity with the ceramic hole to result in the best possible vantage point for final inspection. Fiber Optic Center will then provide a failure mode interpretation and suggest cause or source of the failure. Photographic documentation with various magnifications, illumination techniques and microscopes will be included to illustrate this analysis. Sample illustrations and analyses of cross-sections performed by Fiber Optic Center.
Observations: This particular connector had multiple fractures inside ceramic ferrule (photo A.1-A.3) and a substantial length of fiber missing. See photos A.2 and A.3. From the location of the missing fiber, it appears that the section of fiber came out during assembly prior to thermal curing. This particular fiber received substantial shock during the assembly process (during the fiber insertion). I have seen this before with tight fitting ferrules where fiber was fractured and broken off inside ceramic ferrule while trying to push the fiber thru the hole. Not knowing exactly what hole size this is it appears that the cause of the failure is related to how the fiber was inserted into the ferrule.
This connector has (1) distinctive fiber fracture at the beginning of the ceramic internal chamfer (photo B.2). I did notice more than usual “epoxy shrinkage” against the walls internally. This shrinkage during the thermal curing contributed to the fiber fracture where a nick fatigued the fiber and the stresses of thermal curing and shrinkage actually separated the fiber at this location. The remaining fiber trapped inside the shaft of the ferrule acted as an anchor point. This is the most common problem created by the nicking of the fiber from the improper use of mechanical strippers or misaligned blades.
Observations: There is a substantial gap between the end of the stripped buffer area to the point of breakage (just inside the internal chamfer of the ceramic ferrule). Also evident is the shrinkage of epoxy which is quite apparent against the chamfer. It appears that the epoxy inside the ferrule cured first and acted as an anchor point during the thermal curing process. As the thicker regions of epoxy were curing either accidental backward movement of the fiber pulled and fractured the fiber, creating the visible gap, or the rapid shrinkage of the epoxy pulled everything and “separated” from the anchored fiber inside the ferrule. For more information about this valuable service call Technical support @ 1-800-is fiber (1-800-473-4237)
Fiber Optic Center now offers the full equipment package and training to companies for their own internal cross sectioning service through a third party.