CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is being filed on December 14, 2022, as a PCT International application and claims the benefit of and priority to Chinese Application No. 202111525167.6, filed on December 14, 2021, titled MULTI-FIBER FERRULE FOR MULTI-FIBER OPTICAL CONNECTOR AND MANUFACTURING METHOD THEREOF, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to the field of optical fiber communications in general. More particularly, the present disclosure relates to a multi-fiber ferrule for a multi-fiber optical connector and a manufacturing method thereof.

BACKGROUND ART

[0003] A multi-fiber optical connector (such as an MPO connector) usually includes a connector housing that supports a multi-fiber ferrule. The multi-fiber ferrule may include a row of optical fiber openings and the ends of a plurality of optical fibers are secured in the row of optical fiber openings (for example, by bonding materials, such as epoxy resin). The multi-fiber ferrule may also include pin openings, and the row of optical fiber openings is positioned between the pin openings. In the case of a male multi-fiber connector, an alignment pin is mounted within the pin opening of the male multi-fiber ferrule, and the alignment pin protrudes forward from a front end face of the male multi-fiber ferrule. In the case of a female multi-fiber connector, the pin opening of a female multi-fiber ferrule remains open so as to be capable of receiving the alignment pin of the male multi-fiber ferrule when the male and female ferrules are mated together. Examples of multi-fiber optical connectors are disclosed in US patent Nos. US5,214,730, US6,085,003 and US8,684,611.

SUMMARY OF THE INVENTION

[0004] One of the objects of the present disclosure is to provide a ferrule for an optical fiber connector and a processing method thereof, which can overcome at least one defect in the prior art.

[0005] One aspect of the present disclosure relates to a method for manufacturing a multi-fiber ferrule for a multi-fiber optical connector, the multi-fiber ferrule including a front end and a rear end, the front end and the rear end being provided with a central portion in a lateral direction, and a first side portion and a second side portion on two sides of the central portion, the multi-fiber ferrule being provided with one or more rows of optical fiber openings extending longitudinally through the central portion of the front end and used for receiving optical fibers, the multi-fiber ferrule being provided with a first pin opening and a second pin opening for receiving an alignment pin on two lateral sides of the one or more rows of optical fiber openings, the first pin opening extending longitudinally through the first side portion of the front end and the first side portion of the rear end, and the second pin opening extending longitudinally through the second side portion of the front end and the second side portion of the rear end, the method comprising:

[0006] providing one or more barriers at the front end, the one or more barriers being arranged between the one or more rows of optical fiber openings and the first pin opening, and between the one or more rows of optical fiber openings and the second pin opening, and having at least a portion that extends further forward than the first side portion and the second side portion;

[0007] filling an adhesive into the one or more rows of optical fiber openings, wherein the one or more barriers are configured to prevent the adhesive from entering the first and second pin openings; and [0008] inserting the optical fibers forward through the one or more rows of optical fiber openings to an outer surface of the front end, and using the adhesive to secure the optical fibers in the one or more rows of optical fiber openings.

[0009] In some embodiments, in the step of providing a barrier at the front end, the barrier is added to the front end of the multi-fiber ferrule by an additive process after the ferrule is molded.

[0010] In some embodiments, the additive process is selected from a group consisting of the following: printing, painting and stamping.

[0011] In some embodiments, in the step of providing a barrier at the front end, the barrier is integrally formed with the multi-fiber ferrule concurrent with molding of the multi-fiber ferrule.

[0012] In some embodiments, after the adhesive has cured, the front end of the multi-fiber ferrule is polished by a polishing process to remove the barrier and excess adhesive.

[0013] In some embodiments, the barrier forms a closed wall around all the optical fiber openings.

[0014] In some embodiments, the barrier is formed into a section of wall, the section of wall having a concave side facing toward the central portion of the front end, and a planar side facing toward the first side portion or the second side portion.

[0015] In some embodiments, the barrier is formed into a section of wall, the section of wall having a planar side facing toward the central portion of the front end, and a planar side facing toward the first side portion or the second side portion.

[0016] Another aspect of the present disclosure relates to a multi-fiber ferrule for multi-fiber optical connectors, wherein the multi-fiber ferrule comprises:

[0017] a front end and a rear end, the front end and the rear end being provided with a central portion in a lateral direction, and a first side portion and a second side portion on two sides of the central portion;

[0018] one or more rows of optical fiber openings for receiving optical fibers, the one or more rows of optical fiber openings extending longitudinally through the central portion of the front end;

[0019] a first pin opening and a second pin opening for receiving an alignment pin, the first pin opening and the second pin opening being provided on two lateral sides of the one or more rows of optical fiber openings, the first pin opening extending longitudinally through the first side portion of the front end and the first side portion of the rear end, the second pin opening extending longitudinally through the second side portion of the front end and the second side portion of the rear end; and [0020] one or more barriers at the front end, the one or more barriers being arranged between the one or more rows of optical fiber openings and the first pin opening, and between the one or more rows of optical fiber openings and the second pin opening, and having at least a portion that extends further forward than the first side portion and the second side portion, the one or more barriers being configured to prevent an adhesive, which is filled into the one or more rows of optical fiber openings, from entering the first and second pin openings.

[0021] In some embodiments, the barrier is added to the front end of the multi-fiber ferrule by an additive process after the ferrule is molded.

[0022] In some embodiments, the additive process is selected from a group consisting of the following: printing, painting and stamping.

[0023] In some embodiments, the barrier is integrally formed with the multi-fiber ferrule concurrent with molding of the multi-fiber ferrule.

[0024] In some embodiments, the barrier is configured to be removed by polishing after the adhesive has cured.

[0025] In some embodiments, the barrier forms a closed wall around all the optical fiber openings.

[0026] In some embodiments, the barrier is formed into a section of a wall, the section of the wall having a concave side facing toward the central portion of the front end, and a planar side facing toward the first side portion or the second side portion.

[0027] In some embodiments, the barrier is formed into a section of a wall, the section of the wall having a planar side facing toward the central portion of the front end, and a planar side facing toward the first side portion or the second side portion. [0028] It should be noted that various aspects of the present disclosure described for one embodiment may be included in other different embodiments, even though specific description is not made for the other different embodiments. In other words, all the embodiments and/or features of any embodiment may be combined in any manner and/or combination, as long as they are not contradictory to each other.

DESCRIPTION OF ATTACHED DRAWINGS

[0029] A plurality of aspects of the present disclosure will be better understood after reading the following specific embodiments with reference to the attached drawings. Among the attached drawings:

[0030] Figs. 1 A and IB respectively show a perspective view of an assembled state, and a perspective view of a disassembled state of a multi-fiber optical connector according to an embodiment of the present disclosure;

[0031] Figs. 2A and 2B respectively show a top view and a front view of a multi-fiber ferrule of Figs. 1A and IB; and

[0032] Figs. 3 to 5 respectively show perspective views of a barrier of the multi-fiber ferrules of Figs. 1A and IB according to different embodiments.

[0033] It should be understood that in all the attached drawings, the same symbols denote the same elements. In the attached drawings, for clarity, the size of certain feature is not drawn to scale as it may change.

SPECIFIC EMBODIMENTS

[0034] The present disclosure will be described below with reference to the attached drawings, and the attached drawings illustrate certain embodiments of the present disclosure. However, it should be understood that the present disclosure may be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the content of the present disclosure more complete and to fully explain the protection scope of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed in the present disclosure may be combined in various ways so as to provide more additional embodiments.

[0035] It should be understood that the words in the Specification are only used to describe specific embodiments and are not intended to limit the present disclosure. Unless otherwise defined, all terms (including technical terms and scientific terms) used in the Specification have the meanings commonly understood by those skilled in the art. For brevity and/or clarity, well-known functions or structures may not be further described in detail.

[0036] The singular forms “a”, “an”, “the” and “this” used in the Specification all include plural forms unless clearly indicated. The words “include”, “contain” and “have” used in the Specification indicate the presence of the claimed features, but do not exclude the presence of one or a plurality of other features. The word “and/or” used in the Specification includes any or all combinations of one or a plurality of the related listed items.

[0037] In the Specification, when it is described that an element is “on” another element, “attached” to another element, “connected” to another element, “coupled” with another element, or “in contact with” another element, etc., the element may be directly on another element, attached to another element, connected to another element, coupled with another element, or in contact with another element, or an intermediate element may be present.

[0038] In the Specification, the terms “first”, “second”, “third”, etc. are only used for convenience of description and are not intended for limitation. Any technical features represented by “first”, “second”, “third”, etc. are interchangeable.

[0039] In the Specification, terms expressing spatial relations such as “upper”, “lower”, “front”, “rear”, “top”, and “bottom” may describe the relation between one feature and another feature in the attached drawings. It should be understood that, in addition to the locations shown in the attached drawings, the words expressing spatial relations further include different locations of a device in use or operation. For example, when a device in the attached drawings is turned upside down, the features originally described as being “below” other features now can be described as being “above” the other features”. The device may also be oriented by other means (rotated by 90 degrees or at other locations), and at this time, a relative spatial relation will be explained accordingly.

[0040] In the Specification section, a direction along the central axis of the multi-fiber optical connector is referred to as the longitudinal direction or front-rear direction, and a direction perpendicular to the longitudinal direction and perpendicular to the left and right end faces of the multi-fiber optical connector is referred to as the lateral direction.

[0041] Figs. 1 A and IB respectively show a perspective view of an assembled state and a perspective view of a disassembled state of a multi-fiber optical connector 20 (described with an MPO connector as an example) according to an embodiment of the present disclosure. As shown in the figures, the multi-fiber optical connector 20 may comprise a connector body 23, a release sleeve 24 and a spring pusher 28. The spring pusher 28 is loaded into a rear end 23b of the connector body 23. The release sleeve 24 is mounted on the connector body 23 and can slide back and forth within a limited range along the longitudinal direction relative to the connector body 23. The release sleeve 24 can be spring-biased in the forward direction and can be retracted from the front position to release the connector 20 from a mating fiber optic adapter (not shown). The multi-fiber optical connector 20 may further include a dust cap 22 mounted on a front end 23a of the connector body 23, and a connector boot 26 mounted on the rear end of the spring pusher 28.

[0042] The connector body 23 may have an internal passageway 25, and the internal passage 25 extends from the front end 23a of the connector body 23 to the rear end 23b along a central axis 21. A ferrule assembly 33 mounts within the internal passageway 25 of the connector body 23. The ferrule assembly 33 includes a multi-fiber ferrule 36, a ferrule boot 34 and an alignment pin assembly 35. The multi-fiber ferrule 36 and the ferrule boot 34 are used to support and position an optical fiber 39 of an optical fiber ribbon 41. The alignment pin assembly 35 is mounted on the ferrule 36 to provide fiber alignment between male and female ferrules.

[0043] Figs. 2A and 2B respectively show a top view and a front view of the multi-fiber ferrule 36 according to an embodiment of the present disclosure. In combination with Figs. 1A and IB, the multi-fiber ferrule 36 has a substantially rectangular parallelepiped shape, and has an elongated front end 36a and an elongated rear end 36b. The front end 36a of the ferrule 36 is provided with a central portion 76 in its lateral direction, and symmetrical first side portion 72 and second side portion 74 on two sides of the central portion. The central portion 76 of the front end 36a may be set to be leveled with the first side portion 72 and the second side portion 74, or set to be higher or lower than the first side portion 72 and the second side portion 74. Accordingly, the rear end 36b of the ferrule 36 is provided with a central portion along its lateral direction, and symmetrical first side portion and second side portion located on two sides of the central portion.

[0044] The central portion of the rear end 36b is provided with a concave portion. The ferrule boot 34 mounts within the concave portion for receiving the optical fiber ribbon 41 and guiding the optical fiber ribbon 41 into the rear end 36b. The central portion 76 of the front end 36a is provided with one or more rows of optical fiber openings 37. These optical fiber openings 37 pass through the front end 36a along the longitudinal direction and are connected to the concave portion of the rear end 36b. These optical fiber openings 37 are adapted for receiving and supporting the ends of the optical fiber 39 broken out from a matrix material 43 of the optical fiber ribbon 41. The optical fiber openings 37 in different rows correspond to different optical fiber ribbons 41. Each opening of each row of optical fiber openings 37 is arranged in a roughly lateral direction and separated from each other. In some samples, each row of optical fiber openings 37 has 12 openings so as to receive 12 optical fibers. In some examples, an end face of the optical fiber 39 is positioned at the outer surface of the front end 36a of the ferrule 36. After assembling the ferrule 36 into the connector body 23, the front end 23a of the connector body 23 can be close to the front end 36a of the ferrule 36, making it easy to optically connect with a matching multi-fiber optical connector.

[0045] The ferrule 36 is provided with a first pin opening 51a and a second pin opening 51b on two sides of the optical fiber opening 37 to receive used to receive an alignment pin 32 (which will be described in detail later). The first pin opening 51a extends through the first side portion 72 of the front end 36a and the first side portion of the rear end 36b, while the second pin opening 51b extends through the second side portion 74 of the front end 36a and the second side portion of the rear end 36b.

[0046] The alignment pin assembly 35 includes a pair of alignment pins 32, and the rear ends of the alignment pins 32 are supported within a pin base 59. The pin base 59 mounts at the rear end 36b of the ferrule 36, and the two alignment pins 32 are respectively inserted into the pin openings 51a and 51b of the ferrule 36. When the ferrule 36 is a male multi-fiber ferrule, the alignment pins 32 pass through the pin openings 51a and 51b and protrude forward exceeding the outer surface of the front end 36a of the ferrule 36. When the ferrule 36 is a female multi-fiber ferrule, the pin base 59 supports shorter alignment pins 32, and these shorter alignment pins 32 extend only a relatively short distance forward within the pin openings 51a and 51b such that front portions of the pin openings 51a and 51b are open. In use, the alignment pins 32 of the male multi-fiber ferrule are adapted to be inserted into the corresponding pin openings 51a and 51b of the female multi-fiber ferrule to provide alignment between the optical fibers of the male and female ferrules.

[0047] The ferrule 36 can be manufactured using a molding process. In one example, the ferrule 36 is made of a material containing a polymeric composition (e.g., a glass-fiber filled polymer such as polyphenylene sulfide). The optical fiber opening 37 and the pin openings 51a and 51b can be formed within the ferrule 36 during molding. The first pin opening 51a and the second pin opening 51b are spaced apart from one another along the lateral direction and are defined as first side portion 72 and second side portion 74 passing through the front end 36a, and first side portion and second side portion passing through the rear end 36b of the ferrule 36. The optical fiber openings 37 extend through a central portion 76 of the front end 36a of the ferrule 36. After molding, an adhesive (such as epoxy resin material) is filled (for example, injection, etc.) into the optical fiber openings 37, and the optical fibers 39 extend forward passing through the optical fiber openings 37 and are secured by the adhesive. After the adhesive has cured, the front end 36a of the ferrule 36 is polished to remove excess adhesive from the front end 36a of the ferrule and to polish the end face of the optical fibers 39. Thereafter, the alignment pins 32 are secured in the pin openings 51a and 51b.

[0048] During the process of securing the optical fibers 39 in the fiber openings 37 by adhesive, the adhesive may flow freely on the outer surface of the front end 36a of the ferrule 36 and accidentally enter the pin openings 51a and 51b. The adhesives in the pin openings 51a and 51b is difficult to remove and may interfere with the mounting of the alignment pins 32 for a male connector. In the case of a female connector, the presence of an adhesive in the pin openings 51a and 51b may prevent proper mating of the female connector and the male connector.

[0049] As shown in Fig. 3, the multi-fiber ferrule 36 is provided with a barrier 90 on the outer surface of the front end 36a to prevent the adhesive used to secure the optical fibers 39 in the fiber openings 37 from entering the pin openings 51a and 51b on two sides. The barrier 90 protrudes forward from the outer surface of the front end 36a and forms a closed wall around all the optical fiber openings 37. The cross section of the wall can be substantially rectangular, circular, or of any suitable shape. In some examples, the barrier 90 may include at least a portion that extends further forward than the first and second side portions 72 and 74 of the ferrule 36. In certain examples, the barrier 90 can include a material having a hydrophobic composition or other composition having physical/ chemical properties adapted to repel an adhesive such as epoxy. [0050] Fig. 4 shows another embodiment of the barrier. As shown in the figure, a barrier 110 is provided on the front end 36a and forms a section of wall at a region between the fiber openings 37 and the pin opening 51a and 51b. The wall protrudes forward from the outer surface of the front end 36a, and has concave sides 112 that face toward the central portion 76 of the front end 36a, and planar sides 114 that face the first side portion 72 or the second side portion 74. The barrier 110 may include at least a portion that extends further forward than the first and second side portions 72 and 74 of the ferrule 36.

[0051] Fig. 5 shows another embodiment of the barrier. As shown in the figure, a barrier 120 is provided on the front end 36a and forms a section of wall at a region between the fiber openings 37 and the pin openings 51a and 51b. The wall protrudes forward from the outer surface of the front end 36a, and has planar sides 122 that face the central portion 76 of the front end 36a, and planar sides 124 that face respectively toward the first and second side portions 72 and 74. The barrier 120 may include at least a portion that extends further forward than the first and second side portions 72 and 74 of the ferrule 36.

[0052] The barrier according to the embodiments of the present disclosure may be made by various methods. In one example, the barrier can be added to the front end 36a of the ferrule 36 after the ferrule 36 is molded. For example, the barrier can be added to (such as adhered to) the front end 36a of the ferrule 36 by an additive process (such as printing, painting, and stamping). In another example, the barrier can be integrally formed with the ferrule 36 concurrent with molding of the ferrule 36.

[0053] The barrier according to the embodiments of the present disclosure can effectively block the adhesive from reaching the pin openings 51a and 51b on the two sides of the optical fiber openings 37 while keeping basic design of the ferrule 36. After the adhesive has cured, the front end 36a of the ferrule 36 is polished by a polishing process. The polishing operation not only removes excess adhesive and polish the end faces of the optical fibers 39, but also removes the barrier. [0054] Exemplary embodiments according to the present disclosure have been described above with reference to the attached drawings. However, those of ordinary skill in the art should understand that various changes and modifications can be made to the exemplary embodiments of the present disclosure without departing from the gist and scope of the present disclosure. All changes and modifications are included in the protection scope of the present disclosure defined by the claims. The present disclosure is defined by the attached claims, and equivalents of these claims are also included.