WO2005107990A1

WO2005107990A1 - Method of soldering using soft beam

Info

Publication number: WO2005107990A1
Application number: PCT/KR2004/002134
Authority: WO
Inventors: Jongdae Sim
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-11
Filing date: 2004-08-24
Publication date: 2005-11-17
Anticipated expiration: 2006-11-11
Also published as: KR100595888B1; KR20050108092A

Abstract

The present invention provides a method of soldering using a soft beam to connect a first collimator and a second collimator with the housing, respectively, the housing having both ends being penetrated, the method comprising the steps of inserting the first collimator in one end of the housing; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the first collimator; soldering the housing and the first collimator by irradiating a soft beam to the solder; inserting the second collimator in the other end of the housing so that the second collimator is separated from the first collimator; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the second collimator; and soldering the housing and the second collimator by irradiating a soft beam to the solder. According to said method, since the contact portion between the housing and the collimator is soldered using a soft beam, a work time is shortened and a range of temperature to guarantee a stable operation increases, compared to the related art bonding process using epoxy.

Description

Description METHOD OF SOLDERING USING SOFT BEAM Technical Field

[1] The present invention relates to a method of soldering using a soft beam, and more particularly, to a method of soldering using a soft beam to solder a contact portion between a housing and a collimator with a soft beam in a process of bonding each collimator with the housing, respectively. Background Art

[2] In general, passive devices for optical communications linearly process light generated from a light source unlike active devices which perform functions of amplification and oscillation. The passive device includes an optical connector to connect optical fibers via a connector, an optical switch to switch an optical path by mechanically driving an optical device, an optical attenuator to attenuate the intensity of light used in optical communications continuously or at a constant interval, an optical coupler to distribute an optical signal received from one point over many points or condense optical signals received from many points at one point, an optical branching filter to multiplex many optical signals having different wavelengths, and an optical combiner to output light received from many input optical fibers through output optical fibers in the number less than that of the input optical fibers.

[3] Among the passive devices for optical communications, the optical attenuator has a typical structure as shown in FIG. 1 and the optical switch has a typical structure as shown in FIG. 2.

[4] Referring to FIG. 1, in the operation of the optical attenuator, the optical attenuator attenuates the intensity of light incoming through an optical fiber 10 by about 0.5 db to 50 db using a lens 20 and a variable filter 30.

[5] Referring to FIG. 2, in the operation of the optical switch, light incoming from a common 11 is transmitted to a transmitter 14. When current is cut off, a mirror 32 automatically blocks between collimators 22, so that the light incoming from a common 11 is reflected by the mirror 32 to proceed in the direction of a reflection 12, thereby being blocked not to proceed in the direction of the transmitter 14.

[6] These related art passive devices for optical communications such as optical attenuators and optical switches are formed by connecting each collimator with a housing respectively. Herein, epoxy is generally used to bond the collimators with the housing. However, epoxy requires a long time to be hardened, so that production amount per unit hour is limited, for example, 1 unit per 120 minutes. Also, after a device is manufactured, it is guaranteed that the device stably operates only within a range of zero to 60 °C due to the physical property of epoxy.

[7] As a result, mass production of optical attenuators and optical switches is so difficult that price competitiveness is deteriorated. Moreover, in spite of a high price, stability in quality is lowered. Therefore, a new method of soldering using a soft beam is needed to solve said problems. Disclosure of Invention Technical Problem

[8] To solve the above and/or other problems, the present invention provides a method of soldering using a soft beam to solder a contact portion between a housing and a collimator with a soft beam in a process of bonding each collimator with the housing, respectively.

[9] Also, the present invention provides a method of soldering using a soft beam in which solder is supplied through a supply hole formed at the upper and the lower portions of the housing in a process of bonding each collimator with the housing, respectively.

[10] Also, the present invention provides a method of soldering using a soft beam with a housing in which a variable filter can be inserted in a space between collimators in a process of bonding each collimator with the housing, respectively.

[11] Also, the present invention provides a method of soldering using a soft beam with a housing in which a mirror for switching can be inserted in a space between two collimators

[12] in a process of bonding each collimator with the housing, respectively. Technical Solution

[13] According to an aspect of the present invention, the present invention provides a method of soldering using a soft beam to connect a first collimator and a second collimator with the housing, respectively, the housing having both ends being penetrated, the method comprising the steps of inserting the first collimator in one end of the housing; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the first collimator; soldering the housing and the first collimator by irradiating a soft beam to the solder; inserting the second collimator in the other end of the housing so that the second collimator is separated from the first collimator; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the second collimator; and soldering the housing and the second collimator by irradiating a soft beam to the solder.

[14] The housing is formed of a metallic material and has a tubular shape.

[15] The housing has at least one supply hole formed at the upper and the lower por tions thereof , and the solder is supplied through the supply hole in supplying solder at a contact portion between an inner circumferential surface of the housing and an outer circumferential surface of the first collimator and in supplying solder at a contact portion between the inner circumferential surface of the housing and an outer circumferential surface of the second collimator, respectively.

[16] The soft beam is an infrared ray having a wavelength in a range of 790 to 830 nm.

[17] The housing has an insertion hole in which a variable filter is inserted and the insertion hole is a space formed by separating the first collimator and the second collimator.

[18] Each of the first collimator and the second collimator is a single collimator.

[19] The housing has an insertion hole in which a mirror for switching is inserted and the insertion hole is a space formed by separating the first collimator and the second collimator.

[20] The first collimator is a single collimator and the second collimator is a dual collimator.

[21] The housing has an insertion hole in which one of gas, liquid, or solid which changes at least one of an optical path and optical power is injected and the insertion hole is a space formed by separating the first collimator and the second collimator.

[22] The first collimator and the second collimator include a pigtail to connect an optical fiber, a lens, a glass tube to connect the pigtail and the lens, and a metallic tube encompassing an outer circumference of the glass tube.

[23] The solder is supplied in a form of wire. Advantageous Effects

[24] As described above, the method of soldering using a soft beam according to embodiments of the present invention has the following effects.

[25] First, by soldering the contact portion between the housing and the collimator using a soft beam in the process of bonding each collimators with the housing respectively , a work time is shortened and a range of temperature to guarantee a stable operation increases from the range of zero to 60 ° C to that of -20 to 80 ° C, compared to the related art bonding process using epoxy.

[26] Second, by supplying solder through the supply hole formed at the upper and the lower portions of the housing in the process of bonding each collimators with the housing respectively , products in which the two collimators and the housing are firmly soldered together can be manufactured easily. [27] Third, by using the housing in which the variable filter can be inserted in the space between the two collimators in the process of bonding each collimator with the housing respectively , a basis for mass production of optical attenuators guaranteeing stable operation can be established. [28] Fourth, by using a housing in which a mirror for switching can be inserted in the space between the two collimators in the process of bonding each collimator with the housing respectively, a basis for mass production of optical switches guaranteeing stable operation can be established. Description of Drawings [29] FIG. 1 is a view illustrating the operation of a general optical attenuator;

[30] FIG. 2 is a view illustrating the operation of a general optical switch;

[31] FIG. 3 is a view illustrating the configuration of an apparatus to perform a method of soldering using a soft beam according to an errbodiment of the present invention; [32] FIG. 4 is a flow chart for explaining a method of soldering using a soft beam according to an errbodiment of the present invention; [33] FIG. 5 is a graph showing the operation of a soft beam in the method shown in FIG. 4; and [34] FIG. 6 is a graph showing the speed of supplying solder in the method shown in FIG. 4. Best Mode [35] Referring to FIG. 3, a method of soldering using a soft beam according to an errbodiment of the present invention include an upper holding unit 102, a lower holding unit 104, a housing holding unit 106, a solder supplying unit 110, a soft beam generator 120, an auto-aligner 130, and a control unit 140. [36] Herein, the soft beam refers to an infrared ray having a wavelength range of 790 to 830 nm as a heat source to solder a housing 150 and first and second collimators 156 and 158 by melting solder. [37] The upper holding unit 102 holding the single or dual second collimator 158 may be a chuck connected to an LM-guide and capable of linearly moving up and down. [38] The lower holding unit 104 holding the single or dual first collimator 156 may be a chuck capable of moving in x, y, and z directions, that is, back and forth, left and right, and up and down; and fixed to a particular position. [39] The upper holding unit 102 and the lower holding unit 104 are driven by a rotary encoder converting a mechanical variation into an electric pulse and a stepping motor controlled by a pulse; has a function to determine self -position; and can be driven manually or automatically by a program.

[40] The housing holding unit 106 holding the housing 150 with which the first and second collimators 156 and 158 are bonded can move up and down, and left and right; and can be controlled to automatically supply the housing 150.

[41] The solder supplying unit 110 supplying solder in a form of wire to a contact portion between the housing 150 and the two collimators 156 and 158 may comprise a friction wheel, an encoder, and a stepping motor. The solder may be a metallic alloy having a melting point of 170 to 190 ° C.

[42] The solder supplying unit 110 can manually or automatically be moved up and down, and left and right by a program. For smoothly supplying solder, the solder supplying unit 110 may be controlled to systematically operate with the soft beam generator 120 by the program.

[43] The soft beam generator 120 soldering the housing 150 and the first and second collimators 156 and 158 by melting solder may include a lamp portion 122, a lens portion 124, and an optical fiber 126 connecting the lamp house lamp portion 122 and the lens portion 124. The lamp portion 122 includes a lamp generating an infrared ray having a wavelength of 790 to 830 nm. The lens portion 124 may include a convex lens capable of adjusting a focus.

[44] The lens portion 124 can heat a portion needing soldering in a non-contact state. Since the lens portion 124 is connected to the lamp portion 122 by the optical fiber 126, it can be smoothly moved to other position to be heated.

[45] The auto-aligner 130 may include a return loss estimator estimating a loss of light returning in a direction opposite to a proceeding direction of the light, an optical power meter, and a tunable laser source.

[46] The control unit 140 manually or automatically controls the upper holding unit 102, the lower holding unit 104, the housing holding unit 106, the solder supplying unit 110, the soft beam generator 120, and the auto-aligner 130 by the program.

[47] The method of soldering using a soft beam according to the errbodiment of the present invention can be used in a method of manufacturing a passive device for optical communications including a bonding process in which the first and second collimators 156 and 158 are connected with the housing 150, respectively, the housing having both ends being penetrated. Herein, the passive device for optical commu- nications may be an optical connector, an optical coupler, an optical branching filter, or an optical combiner, preferably, an optical attenuator or an optical switch.

[48] A method of soldering using a soft beam in a method of manufacturing an optical attenuator and an optical switch is described below.

[49] The first and second collimators 156 and 158 generating a parallel beam includes a pigtail to which an optical fiber is connected, a lens, a glass tube where the pigtail and the lens are combined, and a metallic tube encompassing an outer circumference of the glass tube, but is not limited thereto.

[50] For example, the collimator can be errbodied by directly grinding an end of the optical fiber into a lens shape, hardening polymer at the end of the optical fiber in a lens shape, or grinding an end of ceramic ferrule, thereby having a property of the collimator.

[51] The first and second collimators 156 and 158 used in the method of soldering using a soft beam according to the errbodiment of the present invention further include a metallic tube formed of a stainless steel material, unlike the related art passive device for optical communications such as the optical attenuator and the optical switch manufactured using epoxy.

[52] The metallic tube makes the first and second collimators 156 and 158 easily soldered on an inner circumferential surface of the housing 150. To this end, the metallic tube may be plated with gold after being plated with nickel.

[53] The first and second collimators 156 and 158 may be single or dual collimators according to the nurrber of strands of optical fibers connected to the pigtail.

[54] The housing 150 is an intermediary means for connecting two first and second collimators 156 and 158 and may be formed of a metallic material as a frame having both ends being penetrated. The outer circumference of the housing 150 may be polygonal shape such as rectangular, but tubular shape is preferable.

[55] One or more supply holes 152 can be formed at the upper and the lower portions of the housing 150. The supply holes 152 are formed to supply solder to contact portions of the housing 150 and the first and second collimators 156 and 158 inserted in the housing 150. Preferably, each of the two supply holes 152 may be formed at upper portion and lower portion of the housing 150, respectively, wherein the two supply holes 152 penetrate the housing 150 in the direction of diameter thereof so that solder can be supplied through the two solder supplying units 110.

[56] Also, an insertion hole 154, in which a filter or a mirror can be inserted in a space between the two combined first and second collimators 156 and 158 may be formed at the housing 150. Mode for Invention

[57] FIG. 4 is a flow chart for explaining a method of soldering using a soft beam according to an errbodiment of the present invention. Referring to FIG. 4, the method of soldering using a soft beam includes steps of inserting a first collimator (S100), first supplying solder (SI 10), first soldering (S120), inserting a second collimator (S130), second supplying solder (S140), and second soldering (S150).

[58] In the step of inserting the first collimator (S100), the first collimator 156 is inserted in one end of the housing 150. This step may further include a step of performing optical alignment by holding the first and second collimators 156 and 158 using the lower holding unit 104 and the upper holding unit 102, respectively, and performing housing alignment by holding the housing 150 using the housing holding unit 106.

[59] The optical alignment is performed by using the auto aligner 130 including the return loss (RIL) estimator estimating a loss of light returning in a direction opposite to a proceeding direction of the light, the optical power meter, and the tunable laser source. The optical alignment and the housing alignment may be automatically performed by the control unit 140 according to a preprogrammed program.

[60] After the optical alignment and the housing alignment, the housing holding unit 106 holding the housing 150 descends toward the lower holding unit 104 holding the first collimator 156 so that the first collimator 156 is inserted in the housing 150.

[61] In the step of first supplying solder (SI 10), solder is supplied at a contact portion where an inner circumferential surface of the housing 150 meets an outer circumferential surface of the first collimator 156 through the supply hole 152 of the housing 150. In the step of first soldering (S120), the housing 150 and the first collimator 156 are soldered by irradiating a soft beam to the solder.

[62] The step of first supplying solder (SI 10) and the step of first soldering (S120) are performed systematically with each other. The systematic operation of the step of first supplying solder (SI 10) and the step of first soldering (S120) is illustrated referring to the graphs in FIGS 5 and 6.

[63] FIG. 5 is a graph showing the operation of a soft beam in the method shown in FIG. 4. FIG. 6 is a graph showing the speed of supplying solder in the method shown in FIG. 4.

[64] Referring to FIG. 5, a soft beam is irradiated in three steps of changing power, that is, a preheating step to preheat the contact portion between the housing 150 and the first collimator 156, a heating step to melt the supplied solder, and a post-heating step to discontinue the supply of solder.

[65] Herein, The post-heating step is needed to prevent the supplied solder from being hardened in a state of being combined to the housing 150 when the radiation of a soft beam discontinues just after the heating step in which the solder is melted.

[66] When a single collimator is bonded to the housing 150, a time interval for preheating may be 11 seconds, a time interval for heating may be 7.5 seconds, a time interval for post-heating may be 2 seconds; and a power supplied for preheating may be 27W, a power supplied for heating may be 34W, and a power supplied for post- heating may be 25W.

[67] When a dual collimator is bonded to the housing 150, the a time interval for preheating may be 10 seconds, the a time interval for heating may be 6 seconds, a time interval for post-heating may be 2 seconds; and a power supplied for preheating may be 25W, the a power supplied for heating may be 28W, and the a power supplied for post-heating may be 25W.

[68] Referring to FIG. 6, it is preferred that feeding solder for soldering is made at a time Tl when the preheating step is finished and the heating step starts. Also, it is preferred that stopping supply of the solder and then retracting the solder is made at a time T2 when the heating step is finished and the post heating step starting before the solder is completely hardened is followed thereafter. A speed for supplying solder is 19 mm/s and a speed for retracting solder is -5 mm/s.

[69] The soft beam radiation time, the supplied power, and the solder supply speed are not limited to the above embodiment and can be optimized according to the length of the housing 150 and the standards of the first and second collimators 156 and 158. Also, the time for irradiating soft beam, the supplied power, and the speed of supplying solder may be appropriate values selected to minimize the variation of the value of loss between the first and second collimators 156 and 158 aligned during soldering.

[70] In the step of inserting the second collimator (S130), the second collimator 158 is inserted in the upper end of the housing 150. The second collimator 158 held by the upper holding unit 102 is lowered toward the housing 150 and inserted in the upper end of the housing 150. At this time, the second collimator 158 is located in the housing 150 by being separated from the first collimator 156 bonded to the housing 150.

[71] The step of second supplying solder (S140) and the step of second soldering (SI 50) may be followed after the solder supplying unit 110 and the lens portion 124 of the soft beam generator 120 ascends toward the upper end portion of the housing 150 where the supply hole 152 is located. The other steps are the same as the step of inserting a first collimator (S100), the step of first supplying solder (SI 10), and the step of first soldering (S120).

[72] A combined body of the first collimator 156, the second collimator 158, and the housing 150 made by the method of soldering using a soft beam according to the above-described errbodiment of the present invention can be used for manufacturing of an optical attenuator or an optical switch.

[73] For example, when each of the first and second collimators 156 and 158 is a single collimator, the combined body may be used as a component constituting the optical attenuator. The optical attenuator may be constituted by inserting a variable filter in a space formed between the first and second collimators 156 and 158 separated from each other.

[74] Also, when the first collimator 156 is a dual collimator and the second collimator 158 is a single collimator, the combined body may be used as a component constituting an optical switch. The optical switch may be constituted by inserting a mirror for switching in the space formed between the first and second collimators 156 and 158 separated from each other.

[75] Also, the combined body can be used as a component of a passive device for optical communications for various purposes by injecting gas, liquid, or solid to change an optical path and optical power into the space formed between the first collimator 156 and the second collimator 158, as well as the variable filter or the mirror for switching.

[76] While this invention has been particularly shown and described with reference to preferred errbodiments thereof, it will be understood by those skilled in the art that various changes and modifications in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Industrial Applicability

[77] As described above, the method of soldering using a soft beam according to the present invention can be used in the field of manufacturing passive device for optical communications such as an optical attenuator or an optical switch.

Claims

[1] A method of soldering using a soft beam to connect a first collimator and a second collimator with the housing, respectively, the housing having both ends being penetrated, the method comprising the steps of: inserting the first collimator in one end of the housing; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the first collimator; soldering the housing and the first collimator by irradiating a soft beam to the solder; inserting the second collimator in the other end of the housing so that the second collimator is separated from the first collimator; supplying solder at a contact portion where the inner circumferential surface of the housing meets the outer circumferential surface of the second collimator; and soldering the housing and the second collimator by irradiating a soft beam to the solder.

[2] The method of claim 1, wherein the housing is formed of a metallic material and has a tubular shape.

[3] The method of claim 1, wherein the housing has at least one supply hole formed at the upper and the lower portions thereof , and the solder is supplied through the supply hole in supplying solder at a contact portion between an inner circumferential surface of the housing and an outer circumferential surface of the first collimator and in supplying solder at a contact portion between the inner circumferential surface of the housing and an outer circumferential surface of the second collimator, respectively.

[4] The method of claim 1, wherein the soft beam is an infrared ray having a wavelength in a range of 790 to 830 nm.

[5] The method of claim 1, wherein the housing has an insertion hole in which a variable filter is inserted, and the insertion hole is a space formed by separating the first collimator and the second collimator.

[6] The method of claim 5, wherein each of the first collimator and the second collimator is a single collimator.

[7] The method of claim 1, wherein the housing has an insertion hole in which a mirror for switching is inserted, and the insertion hole is a space formed by separating the first collimator and the second collimator.

[8] The method of claim 7, wherein the first collimator is a single collimator and the second collimator is a dual collimator.

[9] The method of claim 1, wherein the housing has an insertion hole in which one of gas, liquid, or solid which changes at least one of an optical path and optical power is injected, and the insertion hole is a space formed by separating the first collimator and the second collimator.

[10] The method of claim 1, wherein the first collimator and the second collimator include a pigtail to connect an optical fiber, a lens, a glass tube to connect the pigtail and the lens, and a metallic tube encompassing an outer circumference of the glass tube.

[11] The method of claim 1, wherein the solder is supplied in a form of wire.