Talk about fiber optic jumper grinding

Optical fiber connector grinding principle: Use diamond powder or other abrasive particles coated with different sizes of particles on the surface, add abrasive liquid, and put it on a high-speed grinding machine for grinding to obtain the end face, 3D and electrical connectors we need. characteristic.

The general procedure for grinding is as follows:

1. Glue removal: Use 16um, 9um or water sandpaper with a grinding pad or glass pad to remove the 353ND glue on the end face of the Ferrule (ceramic pin) to facilitate the next process.

Precautions:

1. Do not use too much force when removing the glue, so as not to break the fiber optic fiber at the end face and cause the fiber fiber to break in the Ferrule (ceramic ferrule), and cause holes or fiber collapse (laceration) on the end face after grinding.
2. When removing the glue, it needs to be cleaned to avoid the glue residue on the end surface, which will cause the radius of curvature to be inconsistent after grinding.
3. The glue removal time should not be too long. If it is too long, double circles will be generated, which will affect the grinding of the next process.
4. Forming angle (if it is PC, this process is not required)

Angle forming: Usually use 9 um abrasive paper with a certain amount of time, pressure and abrasive liquid to form the ferrule (ceramic pin) that needs to be formed to the angle we need. The common angle in our company is 8 degrees.

Precautions:

1. The grinding time should not be too long to avoid the Ferrule (ceramic pin) being ground short, and the time should not be too short, too short will increase the grinding time of the next step
2. The grinding pressure should not be too high to avoid the Ferrule (ceramic pin) being ground short and cause large holes (fiber collapse) on the end surface after grinding, and it should not be too small, which will increase the grinding time of the next step.
3. 3um (9um) coarse grinding

The grinding of this process is to eliminate the rough scratches and holes after degumming and 16um rough grinding. The grinding time and pressure of this process have a great influence on the end surface and 3D.

Precautions:

1. The grinding time of this process should not be too short, otherwise there will be holes on the end surface and the radius of curvature will be too large.
2. The pressure should not be too high or too low. If the pressure is too high, the abrasive paper will be worn out, and the radius of curvature will be too small; if it is too small, holes will be generated and the radius of curvature will be too large.
3. 1um fine grinding

The grinding of this process is to remove the coarse scratches and holes after 3um (9um) grinding, so that the scratches on the end surface become finer, so as to facilitate the polishing of the next process. The grinding time and pressure of this process have a great influence on the end surface and 3D big.

Precautions:

1. The grinding time of this process should not be too short, otherwise there will be holes on the end surface and the radius of curvature will be too large.
2. The pressure should not be too high or too low. If the pressure is too high, the abrasive paper will be worn out, and the radius of curvature will be too small. If it is too small, holes will be generated and the radius of curvature will be too large.
3. There must be no holes or rough scratches during the end face inspection after grinding in this process, otherwise holes will appear after polishing in the next process.
4. 0.3um polishing

The grinding in this process is to eliminate scratches and holes and increase reflection.

Precautions:

1. The grinding time of this process should not be too short, otherwise there will be scratches and ceramic black spots on the end surface.
2. The grinding pressure should not be too small, otherwise there will be light scratches and ceramic black spots.
3. Only abrasive liquid can be used in this process, otherwise there will be scratches and holes.
4. 0.03um (UP) polishing

The grinding of this process is to apply 0.03um silicon dioxide to the ceramic and fiber optic part of the Ferrule (ceramic ferrule) to eliminate scratches and increase reflection.

Precautions:

1. The grinding time of this process should not be too short, otherwise there will be scratches on the end face.
2. The grinding pressure should not be too small, otherwise there will be slight scratches.
3. This process can only be ground with distilled water or pure water; if the grinding liquid is used, the optical fiber height will have a bad phenomenon of -100nm.
4. Do not touch the surface of this abrasive paper with your hands or wipe it with alcohol, otherwise there will be scratches and holes.
5. Disassemble

The disc removal is to remove the ground product from the grinding disc, so as to facilitate the end face inspection and 3D inspection in the later process.

Precautions:

1. When removing the disk, you cannot directly pull the wire part by hand, but you should hold the Ferrule (ceramic pin) part and remove it one by one.
2. Put them neatly on the tray after dismantling.

Common causes of end face and 3D defects and improvement methods

1. End face
2. Scratches:

Scratches are when the polished Ferrule (ceramic pin) is magnified with a microscope of 200 times or 400 times, and then there are white or black linear scars on the end surface and the ceramic part shown through the monitor.

cause:

1. The grinding time of 3um (9um) and 1um is not enough, and rough scratches or black scratches are easy to occur.
2. The grinding time of 0.3um is not enough, and it is easy to cause scratches.
3. The pressure of 0.3um is not enough, and it is easy to produce light and fine scratches.
4. Distilled water or purified water is unclean and prone to scratches.
5. The 0.3um surface is dirty and prone to scratches.
6. The 0.3um raw material is poor, and it is easy to cause scratches.

Improve methods:

1. Determine whether to increase or decrease the grinding time of 3um (9um), 1um, and 0.3um according to the results of the end face after grinding, and the time cannot be increased or decreased without reason.
2. Determine the grinding pressure according to the end surface after grinding and the 3D results. If the pressure is too high, the grinding paper will be broken, and if the pressure is too small, the 3D results will be affected.
3. For the feeding of abrasive paper, for each production batch, several sheets need to be taken out for grinding test. If there is no problem, it can be sent to the production line for use. If the trial result is not good, the result will be fed back to the purchaser, and the purchaser will give feedback to the supplier.
4. When feeding distilled water, take a part of each barrel for testing, and use it on the production line if there is no problem.
5. Holes

Holes are white bright spots or black spots that cannot be wiped off on the end face and ceramic parts displayed on the monitor after magnifying the ground Ferrule (ceramic pin) with a microscope of 200 or 400 times.

cause:

1. Excessive force when removing the glue may damage the optical fiber and cause holes.

b, 16um grinding time is not enough, easy to produce holes.

c, 3um (9um), 1um grinding time is not enough, the pressure is too small, easy to produce holes.

d, 0.3um is not good, and it is easy to produce holes.

1. The arm of the grinder is uneven.

Improve methods:

1. When removing the glue, pay attention to manually smoothing the fiber optic wire on the end face and not using too much force to remove the glue.
2. Determine the grinding pressure and 16um grinding time according to the results of 16um grinding.
3. Determine the grinding time and pressure of 3um (9um) and 1um according to the results of grinding the end face of 3um (9um) and 1um.
4. If there is no hole in the end surface after 1um grinding, it may be a defect caused by 0.3um, and it is necessary to analyze and improve 0.3um.
5. The arm of the grinder needs to be trimmed regularly.
6. Laceration

The crack is to inspect the end face with a microscope of 200 times or 400 times. When the focal length of the microscope is adjusted, a crack appears on the end face. When the focal length of the microscope is adjusted to the clearest, the crack is the smallest. get bigger.

cause:

1. When cutting the optical fiber, the cutting knife is not sharp and cuts the optical fiber instead of cutting the optical fiber, which causes the optical fiber to break in the Ferrule (ceramic ferrule).
2. Excessive force when removing the glue will break the fiber optic fiber and cause the fiber fiber fiber to break in the Ferrule (ceramic ferrule).
3. Excessive force is applied when testing the elasticity of the connector

Improve methods:

1. The fiber optic cleaver should always check whether it is sharp, and if it is not sharp, it should be replaced in time. Check the cutting knife method Use a cutting knife to scratch the white paper lightly to see if the white paper can be cut through. If it can be cut, it can be used, otherwise the cutting knife needs to be sharpened.
2. When removing the glue, pay attention to manually smoothing the fiber optic wire on the end face and not using too much force to remove the glue.
3. You need to remove the glue first and then try the elasticity.

3D geometry

1. Radius of curvature

The radius of curvature refers to the radius of the convex spherical surface of Ferrule (ceramic pin). PCΦ2.5 is 8~24mm, MuΦ1.25 is 11~24mm, LcΦ1.25 is 8~24mm, APC is 5.5~11.5mm.

Bad reasons:

1. The polishing pad is too hard (R is too large) or too soft (R is too small).
2. The grinding pressure is too large (R is too small) or too small (R is too large).
3. The abrasive paper is severely worn.

Improve methods:

1. According to the 3D inspection results, select the appropriate polishing pad.
2. According to the 3D detection results, adjust the pressure of the grinder to the appropriate level.
3. If it is confirmed that the grinding pad and pressure are correct, check whether the grinding paper is worn, and replace it in time if worn.
4. Vertex offset

Vertex offset refers to the distance between the center of the convex spherical surface of the Ferrule (ceramic pin) after grinding and the center of the Ferrule (ceramic pin). The general requirement is ≤50um.

Bad reasons:

1. Grinding disc offset.
2. The grinding pressure is too small.
3. The grinding pad is hard.
4. If it is APC, there will be a positioning block offset.

Improve methods:

1. Test out which hole of the grinding disc is offset for trimming.
2. According to the 3D detection results, adjust the grinding pressure and grinding pad grinding.
3. After the grinding disc is manufactured, it is necessary to use a projector to measure whether the grinding disc is offset, and it needs to be used in the production line, and the 3D results should be recorded. If the interference ring deviates to the left during 3D detection, the angle of the grinding disc is too small , if it deviates to the right, the angle of the grinding disc is too large; if the interference ring is biased upward, the positioning block is biased upward, and if it is biased downward, the positioning block is biased downward.
4. Fiber height

Fiber height refers to the distance that the fiber filament protrudes or is recessed in the ceramic.

Bad reasons:

1. Distilled water is not clean.
2. 0.3um is dirty and defective.

Improve methods:

1. When feeding distilled water, take a part of each barrel for testing and use it on the production line if there is no problem.
2. When feeding 0.3um materials, for each production batch, it is necessary to take out several pieces for grinding test. If there is no problem, it can be sent to the production line for use. If the trial result is not good, the result will be fed back to the purchaser, and the purchaser will give feedback to the supplier.
3. Angle (8 degrees)

The angle refers to the use of an angled grinding disc to process an inclined angle, usually 8 degrees ± 0.3 degrees.

Bad reasons:

1. The angle of the grinding disc is incorrect.
2. The abrasive pad is too hard or too soft.

Improve methods:

1. Use a projector to measure the angle of the grinding disc.
2. According to the 3D detection results, determine which hole angle of the grinding disc is incorrect.
3. According to the 3D detection results, adjust the hardness of the polishing pad.