Last Updated: August 30, 2019
Most of our customers know the pain when it comes to switching suppliers or changing specification on connectors. The market keeps us sharply informed about new connector versions with attractive pricing while we do not always know the impact of switching from suppliers.
We, at FOC, are regularly exposed to the challenge of helping our customers implement new connector styles, versions and suppliers as well as adjusting assembly techniques that lead to further cost reduction.
We like to give insight when it comes to changing a connector supplier. Let’s say a singlemode SC connector as example….
Starting from the point that the SC is an industrial standard connector, everyone knows that it is standardized on the connection point, meaning that all other area’s like the inner-housing, ferrule size and ferrule shape, housing color, backside and strain relief boot are custom to the manufacturer.
Let’s focus on each section of the connector and share with you some thoughts:
Inner-housing: most of today’s SC connectors are the ‘one-piece’ design which is an assembly of ferrule inner-housing and backside. Often are the outer-housing, crimp sleeve and the strain relief boot in bulk package separately provided. The traditional multi-piece design consist of more piece parts, like separate ferrule and spring and offers more flexibility. Customers can select various ferrule diameters as well as different connector backsides to accommodate bare fiber or different cables. Some of these connectors allows the ability for tuning.
Ferrule size: specification of ferrules is critical to performance. Often we look at the inner diameter but we learn that very limited customers do have the ability for incoming inspection. FOC offers gauge kits to confirm if you receive the right inner diameter in the range of 125-128u in incremental of 0.5um and assure that you receive the quality you’re paying for. It still happens, and most of our customers will agree, that the connector manufacturer change their ferrule supplier. You might not notice this until you polish the connector and discover that you see a change in geometry. The shape of the ferrule is directly related to polishing thus geometry and IL and RL values of the assembly.
Ferrule shape: although SC connectors have a 2.5mm ferrule, you might have noticed that some are flat, domed, conical or step shaped. Each of these forms need a different polishing to achieve perfect geometrical results with the minimal amount of time/cost involved. At FOC, we are developing processes that continuously reduce total installed cost. This means that sometimes a more expensive connector offers a significant advantage as it reduce polishing steps/cost.
Housing color: everyone knows that the industry colors on connector housings are standardized by RAL colors (blue, beige, green), however it’s unfortunately a regular case that blue housings (singlemode) are mixed with 127u ferrules connector housings. These are the cheaper singlemode connectors. Due to the 2u misalignment of the core, IL and RL values are significantly worse. Also here a gauge kit will be instrumental in incoming inspection.
Backside: traditionally SC connectors were accommodated with 3-3.5mm OD cable to withstand the IEC/Telcordia cable pull tests. With the introduction of the smaller LC connector, that accommodate typically smaller OD’s like 2.0 or 1.6mm, the SC connector needed at many manufacturer a re-design to accept 1.6/2.0mm cables. A critical eye on the backside design is needed to match it with the right cable manufacturer, taking the jacket thickness and the amount of Kevlar in consideration.
Strain relief boot: this element will make your product pass or fail on side pull tests. As the boot should nicely cover the cable or 900u buffer, a 90 degree pull should accommodate a nice curve that stays above a radius of 25mm. It is interesting to review your own product and see if the curve is nicely distributed.
Over the course of the blogs we will focus on various connector challenges, developments in various applications. If you have any specific question we would encourage you to contact FOC to work with you finding your solution.
Follow Giorgio at @ConnectorExprt