JP2012226384A - Optical waveguide holding member and optical transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress thermal expansion of an optical waveguide holding member under high temperature environment.SOLUTION: The optical waveguide holding member has: an incident part which an optical signal from an optical fiber enters; an optical waveguide which is formed in a curved surface shape so as to guide the optical signal having entered the incident part to a photoelectric conversion element mounted on a print circuit board; a lens part which emits the optical signal having passed through the optical waveguide to a light receiving/emitting part of the photoelectric conversion element; and a casing part for fixing each of the incident part, the optical waveguide and the lens part. The incident part, the waveguide and the lens part are formed of a resin material, and the casing part is formed of a metal material or a ceramic material.

Description

  The present invention relates to an optical waveguide holding member and an optical transceiver, and in particular, an optical waveguide holding member having an optical waveguide molded with a resin so as to guide an optical signal to a photoelectric conversion element on the printed board and the optical waveguide holding member mounted on the printed board. Related to an optical transceiver.

Conventionally, communication using optical fibers has become mainstream due to the development of high-speed, large-capacity communication networks and communication control devices. For example, signals are transmitted and received by connecting a communication network such as the Internet to an information terminal installed in an office or home by an optical fiber. An optical transceiver capable of bidirectionally converting an electrical signal and an optical signal is used at a connection portion between a server, a personal computer or a peripheral device and an optical fiber (external optical fiber). Such an optical transceiver includes an optical waveguide formed between an external optical fiber and a photoelectric conversion element (see, for example, Patent Document 1).
JP 2005-115346 A

  In the optical transceiver as described above, an optical waveguide holding member having an optical waveguide is mounted on a printed circuit board on which a photoelectric conversion element is disposed. Usually, the printed circuit board is made of glass epoxy resin, while the optical waveguide holding member is made of olefin resin in order to ensure the function as a clad material. The optical path connection between the photoelectric conversion element arranged on the printed circuit board side and the optical waveguide arranged on the optical waveguide holding member side is formed at the light receiving and emitting part of the photoelectric conversion element and the end of the optical waveguide. This is realized by making the lens parts face each other and matching the optical centers thereof. In the optical transceiver, the positional accuracy between the optical centers is required to be ± several μm level.

  By the way, when one printed circuit board is formed using glass epoxy resin as a material, the linear expansion coefficient of the printed circuit board is 13 × 10 −6 / ° C. The linear expansion coefficient of the other optical waveguide is 70 × 10 −6 / ° C. Therefore, for example, when an optical waveguide holding member is mounted on a printed circuit board in an environment of room temperature of 25 ° C., and exposed to an atmosphere of 85 ° C. by heat from a peripheral device, the photoelectric conversion mounted on the printed circuit board The position of the element is displaced to 10.07 mm due to thermal expansion, and the lens portion of the optical waveguide holding member facing the light receiving and emitting part of the photoelectric conversion element is displaced to 10.038 mm. In this case, the relative position shift between the two members is approximately 31 μm.

  As a method for suppressing the relative position shift between the lens portion of the optical waveguide holding member and the light receiving and emitting portion of the photoelectric conversion element due to such thermal expansion, conventionally, in the optical transceiver assembly process, the standard of the optical transceiver is used. By aligning the optical axis in an atmosphere heated to the operating temperature, the optical axis shift due to thermal expansion has been suppressed.

  However, in this manufacturing process, the work is complicated, and a desired positional accuracy (suppression effect) cannot be obtained, resulting in a decrease in yield.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an optical waveguide holding member and an optical transceiver that suppress an optical signal shift due to thermal expansion of the optical waveguide holding member.

  In order to solve the above problems, the present invention has the following means.

  The present invention is made of a resin material and has an incident portion where an optical signal from an optical fiber is incident, and a curved surface shape so as to guide the optical signal incident on the incident portion to a photoelectric conversion element mounted on a printed circuit board And an optical waveguide holding member having an optical waveguide formed on the optical waveguide and a lens unit that emits an optical signal that has passed through the optical waveguide to a light emitting and receiving unit of the photoelectric conversion element. The optical waveguide holding member is formed of a metal material or a ceramic material. By providing the cover member so as to cover the surface of the resin material, the above-described problems are solved.

  The cover member includes an outer cover member that covers the outer side of the optical waveguide and an inner cover member that covers the inner side of the optical waveguide, and has at least one of the outer cover member and the inner cover member. Is desirable.

  The outer cover member has a first opening for transmitting an optical signal to the incident portion, and the inner cover member has a second opening for transmitting an optical signal to a portion facing the lens portion. It is desirable to have

  The cover member may be bonded to a portion of the optical waveguide except for the core portion.

  The outer cover member and the inner cover member are preferably formed of stainless steel.

  The outer cover member and the inner cover member are preferably formed by any one of pressing, casting, and cutting.

  The outer cover member preferably has a slit in a portion facing the core portion of the optical waveguide.

  Further, the present invention is formed in a curved surface shape so as to guide the optical signal incident on the incident portion to which the optical signal from the optical fiber is incident and to the photoelectric conversion element mounted on the printed board. An optical waveguide, a lens unit that emits an optical signal that has passed through the optical waveguide to a light emitting / receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing for fixing each of the lens unit In the optical waveguide holding member, the incident portion, the waveguide, and the lens portion are made of a resin material, and the housing portion is made of a metal material or a ceramic material. Thus, the above-mentioned problem is solved.

  It is desirable that the linear expansion coefficient of the metal material or ceramic material forming the housing portion is lower than the linear expansion coefficient of the resin material.

  The casing is preferably formed by pressing, casting or cutting.

  The incident part, the waveguide, and the lens part are preferably formed by insert molding in the formed casing part.

  The casing is preferably made of a stainless material.

  Further, the present invention is formed in a curved surface shape so as to guide the optical signal incident on the incident portion to which the optical signal from the optical fiber is incident and to the photoelectric conversion element mounted on the printed board. An optical waveguide, a lens unit that emits an optical signal that has passed through the optical waveguide to a light emitting / receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing for fixing each of the lens unit An optical waveguide holding member, wherein the incident portion, the waveguide, and the lens portion are formed of a resin material, and the housing portion is formed of a thermoplastic resin material different from the resin material. By doing so, the above-described problems are solved.

  The linear expansion coefficient of the thermoplastic resin material forming the casing is preferably lower than the linear expansion coefficient of the resin material.

  The casing is preferably formed by injection molding.

  The incident part, the waveguide, and the lens part are preferably formed by double-molding or two-color molding of a resin material in the formed casing.

  Further, the present invention is formed in a curved surface shape so as to guide the optical signal incident on the incident portion to which the optical signal from the optical fiber is incident and to the photoelectric conversion element mounted on the printed board. An optical waveguide, a lens unit that emits an optical signal that has passed through the optical waveguide to a light emitting / receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing for fixing each of the lens unit The incident portion, the waveguide and the lens portion are made of a resin material, and the housing portion is made of a thermosetting resin material different from the resin material. By forming it, the above-mentioned problems are solved.

  The linear expansion coefficient of the thermosetting resin material forming the casing is preferably lower than the linear expansion coefficient of the resin material.

  The casing is preferably formed by cast molding or transfer molding.

  The incident part, the waveguide, and the lens part are preferably formed by double-molding or two-color molding of a resin material in the formed casing.

  The present invention also provides an optical waveguide holding member having a printed circuit board, a photoelectric conversion element mounted on the printed circuit board, and an optical waveguide formed of a resin material and guiding an optical signal incident from an optical fiber to the photoelectric conversion element. In the optical transceiver including the above, the above-described problem is solved by providing a cover member made of a metal material or a ceramic material so as to cover the surface of the optical waveguide holding member.

  The outer cover member and the inner cover member are preferably fixed to the printed circuit board by any one of fixing means such as adhesion, soldering, press fit, and heat welding.

  The optical waveguide holding member is preferably fixed to the printed circuit board by an adhesive, press fit, or soldering.

  According to the present invention, the cover member formed of a metal material or a ceramic material is provided so as to cover the surface of the resin material, and the casing portion is formed of a material having a low expansion coefficient such as metal. Thus, it is possible to suppress the thermal expansion of the resin material and suppress the relative position shift between the end portion of the optical waveguide and the light receiving and emitting portion of the photoelectric conversion element.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing Embodiment 1 of an optical waveguide holding member and an optical transceiver according to the present invention. FIG. 2 is a perspective view showing an assembled state of the outer cover member (indicated by the alternate long and short dash line), the optical waveguide holding member, and the printed board. FIG. 3 is an exploded perspective view illustrating a state before assembly in which the outer cover member is separated from the optical waveguide holding member according to the first embodiment.

  As shown in FIGS. 1 and 2, the optical transceiver 10 has an optical waveguide holding member 30 mounted on a printed circuit board 20. The optical waveguide holding member 30 is covered with an outer cover member 40 formed of a metal material so as to cover the outer surface. The lower portions of the optical waveguide holding member 30 and the outer cover member 40 are fixed on the printed circuit board 20 by an adhesive 22 (shown in a satin pattern in FIG. 2). Although other electronic components are also mounted on the printed circuit board 20, their illustration and description are omitted here.

  As shown in FIGS. 1 and 3, the optical waveguide holding member 30 is made of a resin material as will be described later, and is incident on the incident portion 32 where the optical signal from the optical fiber is incident, and incident on the incident portion 32. The optical waveguide 34 formed in a curved shape so as to guide the optical signal thus obtained to a photoelectric conversion element 70 (see FIGS. 1 and 5) mounted on the printed circuit board 20, and light that has passed through the core portion 34 a of the optical waveguide 34 And a lens unit 36 that emits a signal to the light emitting / receiving unit 72 of the photoelectric conversion element 70. In the present embodiment, the optical waveguide 34 and the core portion 34 a are made of an ultraviolet curable epoxy resin, and the core portion 34 a is inserted into the groove of the optical waveguide 34. Further, the number of the core portions 34a is appropriately selected, and in this embodiment, four core portions 34a are provided in parallel at two locations.

  As shown in FIGS. 1 and 2, the incident portion 32 is provided on the back surface 31 side of the optical waveguide holding member 30 so that an optical fiber connector drawn from a direction parallel to the upper surface of the printed circuit board 20 can be easily connected. ing.

  The plurality of core portions 34 a are formed so as to be connected along the curved surface of the optical waveguide 34 from the incident portion 32 on the back side of the optical waveguide holding member 30 to the lens portion 36 on the lower surface side of the optical waveguide holding member 30. ing. The optical signal transmitted through the optical fiber is transmitted along the core part 34 a, emitted from the lens part 36 in the hanging direction, and is applied to the photoelectric conversion element 70 on the printed circuit board 20 disposed below the lens part 36. To reach.

  As shown in FIG. 4, the lens portion 36 is provided on the lower surface side of the optical waveguide holding member 30 facing the printed circuit board 20. In addition, the lens unit 36 has a plurality of light emitting and receiving units 72 (see FIG. 5) for irradiating the light signal that has passed through the core unit 34 a at positions corresponding to the core unit 34 a of the optical waveguide 34. A spherical lens 36a is provided.

  As shown in FIG. 5, the photoelectric conversion element 70 is mounted at a predetermined position on the printed circuit board 20 so that the plurality of light emitting / receiving units 72 are positioned to face the plurality of spherical lenses 36 a of the lens unit 36. Yes.

  Further, as shown in FIGS. 1 and 2, the optical waveguide holding member 30 includes an upper mounting portion 38 that protrudes upward from the left and right sides of the optical waveguide 34, and a front mounting portion 39 that protrudes forward of the optical waveguide 34. And have. The upper mounting portion 38 and the front mounting portion 39 are fitted and fixed to the outer cover member 40. Further, in the recess 60 formed on the lower surface side of the optical waveguide holding member 30, a leg portion 62 that extends below the front mounting portion 39 and contacts the upper surface of the printed circuit board 20 is formed. Leg portions 64 are formed so as to extend below the upper surface of the printed circuit board 20 and to contact the upper surface of the printed circuit board 20.

  The optical waveguide holding member 30 of the present embodiment is molded from an olefin resin having a function as a cladding material. Further, since the optical waveguide holding member 30 is molded from a resin material, the linear expansion coefficient is approximately 70 × 10 −6 / ° C.

  Since the printed circuit board 20 on which the optical waveguide holding member 30 is mounted is formed of glass epoxy resin, the linear expansion coefficient is 13 × 10 −6 / ° C. Therefore, when thermal expansion accompanying temperature rise occurs between the printed circuit board 20 and the optical waveguide holding member 30, a relative positional shift based on the difference in the linear expansion coefficient occurs.

  The outer cover member 40 is processed with a metal material such as stainless steel (SUS304), and has sufficiently higher rigidity than the resin material. The linear expansion coefficient of the outer cover member 40 is approximately 10.4 × 10 −6 / ° C., which is a value close to the linear expansion coefficient of the printed circuit board 20 (glass epoxy resin). Therefore, the difference in thermal expansion between the outer cover member 40 and the printed circuit board 20 is set to be small.

  Since the outer cover member 40 has a recess 80 corresponding to the outer shape of the optical waveguide holding member 30 (including the optical waveguide 34, the upper mounting portion 38, and the front mounting portion 39), the outer surface of the optical waveguide holding member 30 Can be assembled in close contact with each other. The outer cover member 40 is bonded to the outer surface of the optical waveguide holding member 30 excluding the core portion 34a of the optical waveguide 34.

  Therefore, the optical waveguide holding member 30 is covered with an outer cover member 40 made of a metal material whose outer surface is higher in rigidity than the resin material, and the lower portion together with the outer cover member 40 is fixed to the printed circuit board 20 by the adhesive 22. Therefore, when used in an atmosphere at a temperature higher than room temperature (25 ° C.), the thermal expansion in the X direction and the Y direction of the resin material forming the optical waveguide holding member 30 is restricted by the outer cover member 40. Furthermore, since the optical waveguide holding member 30 protects the outer side of the core part 34a through which the optical signal is transmitted by the outer cover member 40, the core part 34a is prevented from being damaged during the mounting work on the printed circuit board 20.

  The concave portion 80 of the outer cover member 40 is formed so as to have a minute gap between the outer waveguide member 40 and the core portion 34a so as not to be in contact with the optical waveguide 34 during thermal expansion. It is desirable to do so.

  The outer cover member 40 is formed by, for example, a method in which a concave portion 80 corresponding to the outer shape of the optical waveguide holding member 30 is formed by pressing a stainless plate, or a molten stainless material is injected into a mold or a die-cast mold. Then, it is processed by either a method of manufacturing by casting or a method of cutting and manufacturing a metal block made of stainless steel. When the outer cover member 40 is manufactured by casting, it is possible to change the thickness as appropriate, so that the thickness of the portion where the thermal expansion stress acts can be increased, and the outer cover member 40 can be made stronger. Thus, the outer surface of the optical waveguide holding member 30 can be held.

  Further, since it is important that the outer cover member 40 has a concave portion 80 corresponding to the outer shape of the waveguide holding member 30, the outer shape is an upper convex portion 42 corresponding to the outer shape of the optical waveguide holding member 30, A shape having a curved surface 44 and a lower projection 46 may be used, or a box shape without unevenness may be used.

  Further, the outer cover member 40 has a back surface 41 that is in close contact with the back surface 31 of the optical waveguide holding member 30, and the back surface 41 has a first opening 41 a at a portion facing the incident portion 32. The first opening 41a is an opening for inputting an optical signal. The first opening 41a is formed in a rectangular shape elongated in the left-right direction so that the optical fiber side connector can be inserted, and has a length shape corresponding to the width of the incident portion 32. Has been.

  The inner walls of the left and right side surfaces 47 of the outer cover member 40 are formed so that the inner wall surfaces are in close contact with the left and right side surfaces 33 of the optical waveguide holding member 30.

  Further, the step 43 between the upper convex portion 42 and the curved surface 44 is in close contact with the step 38 a of the upper mounting portion 38 of the optical waveguide holding member 30, and the step 45 on the front side of the lower protrusion 46 is the optical waveguide holding member 30. The front mounting portion 39 is formed so as to be in close contact with the step 39a on the front side.

  Thus, the outer cover member 40 has an inner wall shape corresponding to the outer shape of the optical waveguide holding member 30, so that thermal expansion toward the outside in the X direction and the Y direction of the optical waveguide holding member 30 is performed. It becomes possible to restrain. Therefore, the relative positional deviation between the lens portion 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed circuit board 20 is restricted, and the optical signal can be transmitted and received. Can be suppressed.

  According to the optical transceiver 10 configured as described above, since it is not necessary to use a nerve in the temperature environment during the assembly process, the production efficiency of the optical transceiver 10 can be increased, the yield can be improved, and the production can be performed. Improves.

  FIG. 6 is a longitudinal sectional view showing the optical transceiver of the second embodiment. FIG. 7 is an exploded perspective view showing a state before assembly in which the optical waveguide holding member and the inner cover member of Example 2 are separated. 6 and 7, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 6 and 7, in the optical transceiver 10 </ b> A according to the second embodiment, the inner cover member 90 is fitted and fixed to the recess 60 formed on the lower surface side of the optical waveguide holding member 30.

  Similarly to the outer cover member 40 described above, the inner cover member 90 is processed with a metal material such as stainless steel (SUS304) and has sufficiently higher rigidity than the resin material. Further, the linear expansion coefficient of the inner cover member 90 is approximately 10.4 × 10 −6 / ° C., and is set so that the difference in thermal expansion from the printed circuit board 20 becomes small.

  Further, the inner cover member 90 has a bulging portion 91 whose upper surface side corresponds to the shape of the recess 60 of the optical waveguide holding member 30, a horizontal extending portion 92 that covers the lower surface side of the front mounting portion 39, and a bulging portion 91. Side surface 93 that surrounds the left and right direction (X direction), and a back surface 94 that surrounds the back surface side (Y direction) of the bulging portion 91. The horizontal extension portion 92 is formed with a second opening 92a for allowing the optical signal from the lens portion 36 to pass therethrough. The second opening 92 a is a rectangular opening elongated in the left-right direction, and has a length shape corresponding to the lateral width dimension of the lens portion 36.

  Since the inner cover member 90 has a shape corresponding to the upper surface of the recess 60, the front and rear surfaces, the left and right surfaces, and the inner side of the optical waveguide 34, it restrains thermal expansion toward the inner side of the optical waveguide holding member 30 in the X direction and Y direction. It becomes possible to do. Therefore, in the optical transceiver 10A, a relative positional shift due to a difference in thermal expansion between the lens unit 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed board 20 is restrained. Thus, it can be suppressed within the transmission / reception range of the optical signal.

  Thus, according to the optical transceiver 10A of the second embodiment, it is not necessary to use a nerve in the temperature environment during the assembly process, so that the production efficiency of the optical transceiver 10A can be increased, and the yield is also improved. Productivity is improved.

  FIG. 8 is a longitudinal sectional view showing the optical transceiver of the third embodiment. FIG. 9 is an exploded perspective view showing a state before assembly in which the optical waveguide holding member, the outer cover member, and the inner cover member of Example 3 are separated. 8 and 9, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 8 and 9, in the optical transceiver 10B according to the third embodiment, an outer cover member 40 formed so as to cover the outer surface is fitted and fixed to the outside of the optical waveguide holding member 30 to An inner cover member 90 is fitted and fixed in the recess 60 formed on the lower surface side of the waveguide holding member 30.

  Therefore, in the optical waveguide holding member 30, thermal expansion toward the outside in the X direction and the Y direction is restricted by the outer cover member 40, and thermal expansion toward the inside in the X direction and Y direction is restricted by the inner cover member 90. In the optical transceiver 10B of the third embodiment, since the outer cover member 40 and the inner cover member 90 are fitted and fixed to the outer side and the inner side of the optical waveguide holding member 30, it is possible to hold the optical transceiver 10B more firmly. Therefore, according to the optical transceiver 10B, the lens unit 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed circuit board 20 even when used in a higher temperature environment. It is possible to restrain the relative displacement and keep it within the optical signal transmission / reception range.

  Thereby, in the optical transceiver 10B, it is not necessary to use a nerve in the temperature environment at the time of the assembly process, so that the production efficiency of the optical transceiver 10B can be increased, the yield is improved, and the productivity is improved.

  FIG. 10 is a longitudinal sectional view showing an optical transceiver according to the fourth embodiment. FIG. 11 is an exploded perspective view showing a state before assembly in which the optical waveguide holding member, the outer cover member, and the inner cover member of Example 4 are separated. 10 and 11, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 10 and 11, in the optical transceiver 10C according to the fourth embodiment, the outer cover member 140 formed so as to cover the outer surface is fitted and fixed to the outside of the optical waveguide holding member 30 to hold the optical waveguide. An inner cover member 190 is fitted and fixed to the recess 60 formed on the lower surface side of the member 30.

  The outer cover member 140 is processed by a metal material such as stainless steel (SUS304), as with the outer cover member 40 described above. The outer cover member 140 has a back surface 141 that is in close contact with the back surface 31 of the optical waveguide holding member 30, and the back surface 141 has a first opening 141 a at a portion facing the incident portion 32. The first opening 141a is an opening for inputting an optical signal, is formed in a rectangular shape elongated in the left-right direction so that the optical fiber side connector can be inserted, and has a length corresponding to the width of the incident portion 32. It is said that.

  The inner walls of the left and right side surfaces 147 of the outer cover member 140 are formed such that the inner wall surfaces are in close contact with the left and right side surfaces 33 of the optical waveguide holding member 30.

  Further, the upper convex portion 142 and the vertical surface 144 form a relief portion 200 including a step 38 a of the upper mounting portion 38 of the optical waveguide holding member 30 and a space separated from the optical waveguide 34. The step 145 on the front side of the lower protrusion 146 is formed so as to be in close contact with the step 39 a on the front side of the front mounting portion 39 of the optical waveguide holding member 30.

  Thus, the outer cover member 40 has an inner wall shape that does not correspond to the outer shape of the optical waveguide holding member 30, and is formed in a shape that does not contact the outer side of the optical waveguide 34. It is possible to restrain thermal expansion of the optical waveguide holding member 30 toward the outside in the X direction and the Y direction without being compressed. Therefore, the relative positional deviation between the lens portion 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed circuit board 20 is restricted, and the optical signal can be transmitted and received. Can be suppressed.

  Similarly to the inner cover member 90 described above, the inner cover member 190 is processed with a metal material such as stainless steel (SUS304), and has sufficiently higher rigidity than the resin material. Further, the inner cover member 190 has a bulging portion 191 whose upper surface is in contact with the inner wall of the recess 60 of the optical waveguide holding member 30, a horizontal extending portion 192 that covers the lower surface side of the front mounting portion 39, and a bulging portion 191. The side surface 193 enclosing the left-right direction (X direction) and the back surface 194 enclosing the back side (Y direction) of the bulging portion 191. The bulging portion 191 is formed shorter than the length in the Y direction of the concave portion 60 of the waveguide holding member 30 so as not to contact the inside of the optical waveguide 34. Therefore, the vertical surface 195 formed on the front side of the bulging portion 191 forms a clearance portion 210 formed of a space below the optical waveguide 34 so as not to contact the optical waveguide 34.

  Further, the horizontal extension 192 is formed with a second opening 192a for allowing an optical signal from the lens unit 36 to pass therethrough. The second opening 192 a is a rectangular opening elongated in the left-right direction, and has a length shape corresponding to the lateral width dimension of the lens portion 36.

  The inner cover member 190 abuts against the inner wall of the recess 60 of the optical waveguide holding member 30 excluding the optical waveguide 34 (the front and rear left and right rear surfaces 31 of the recess 60, the step 39 a and the inner walls of the left and right side surfaces 33), and the optical waveguide holding member 30. It is possible to restrain thermal expansion toward the inside in the X direction and the Y direction. Therefore, in the optical transceiver 10C, a relative positional shift due to a difference in thermal expansion between the lens unit 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed board 20 is restrained. Thus, it can be suppressed within the transmission / reception range of the optical signal.

  Therefore, in the optical waveguide holding member 30, thermal expansion toward the outside in the X direction and the Y direction is restricted by the outer cover member 140, and thermal expansion toward the inside in the X direction and Y direction is restricted by the inner cover member 190. In the optical transceiver 10C of the fourth embodiment, since the outer cover member 140 and the inner cover member 190 are fitted and fixed to the outer side and the inner side of the optical waveguide holding member 30, the optical waveguide 34 is moved outside by the escape portions 200 and 210. It is possible to clamp more firmly without restraining from the inside.

  Therefore, according to the optical transceiver 10C, the lens unit 36 provided on the lower surface side of the optical waveguide holding member 30 and the photoelectric conversion element 70 mounted on the printed circuit board 20 even when used in a higher temperature environment. It is possible to restrain the relative displacement and keep it within the optical signal transmission / reception range.

  In the optical transceiver 10C according to the fourth embodiment, the outer cover member 140 formed so as to cover the outer surface is fitted and fixed to the outer side of the optical waveguide holding member 30, and is formed on the lower surface side of the optical waveguide holding member 30. The configuration in which the inner cover member 190 is fitted and fixed to the concave portion 60 has been described. However, either the outer cover member 140 or the inner cover member 190 covers the outer side or the inner side of the optical waveguide holding member 30. Also good.

  Hereinafter, modified examples will be described.

  Here, Modification 1 will be described with reference to FIG. As shown in FIG. 12, the outer cover member 40 </ b> A is provided with a plurality of slits 44 a on a curved surface 44 that faces the optical waveguide 34. The plurality of slits 44 a are provided so as to be located at a portion of the optical waveguide 34 facing the core 34 a. This prevents the core 34a of the optical waveguide 34 from being pressed by the outer cover member 40A and receiving stress during thermal expansion.

  In the first modification, the rigidity in the X direction is weakened by the plurality of slits 44a and the strength of restraining the thermal expansion in the X direction of the optical waveguide holding member 30 is reduced. However, the lens unit 36 and the photoelectric conversion element due to thermal expansion are reduced. Since the relative displacement with respect to 70 greatly affects the Y direction, the influence in the X direction can be small.

  Next, Modification 2 will be described with reference to FIG. As shown in FIG. 13, fixing means other than the adhesive 22 described above may be used as means for fixing the outer cover member 40 to the printed circuit board 20.

  For example, as shown in part A in FIG. 13, the fixing end 100 extending downward from the edge of the outer cover member 40 is extended, and the fixing end 100 is inserted into the through hole 123 of the printed circuit board 20. To do. Further, the fixing end portion 100 is fixed to the conductor pattern 124 formed on the printed circuit board 20 by soldering. In this way, the outer cover member 40 may be fixed to the printed circuit board 20 by fixing means using soldering. In this case, the movement in the front-rear and left-right directions (X and Y directions) is constrained by the fixing end portion 100 penetrating the printed circuit board 20. Furthermore, in this A part, since the solder 110 is fixed to the conductor pattern 124 arranged on the lower surface side of the printed circuit board 20 with the solder 110 fixed, displacement of the outer cover member 40 upward (Z direction) is also restrained. Is done.

  In FIG. 13, only one fixing end portion 100 (A portion) is shown, but the outer cover member 40 is firmly attached to the printed circuit board 20 by providing the fixing end portions 100 at a plurality of locations. Can be fixed.

  Thus, by fixing the outer cover member 40 to the printed circuit board 20, it is possible to further suppress the relative positional deviation between the lens unit 36 and the photoelectric conversion element 70 due to thermal expansion in a high temperature environment. .

  Further, as shown in part B in FIG. 13, the fixing end 120 extending downward from the edge of the outer cover member 40 is inserted into the through hole 126 of the printed circuit board 20, and the load is applied by a press machine from the vertical direction. In addition, fixing means for deforming (increasing diameter) the fixing end 120 in the radial direction may be used. Also in this modified example, the outer cover member 40 is fixed to the printed circuit board 20, so that it is possible to further suppress the relative positional deviation between the lens unit 36 and the photoelectric conversion element 70 due to thermal expansion in a high temperature environment. .

  In FIG. 13, only one fixing end portion 120 (B portion) is shown, but the outer cover member 40 is firmly attached to the printed circuit board 20 by providing the fixing end portions 120 at a plurality of locations. Can be fixed.

  Further, as a fixing means other than the above, high heat is applied to a state in which the fixing end 120 extending downward from the edge of the outer cover member 40 is inserted into the through hole 126 of the printed circuit board 20, and A fixing means for melting the portion and fixing the fixing end 120 to the through hole 126 by heat welding may be used. Further, even when this thermal welding method is used, the outer cover member 40 is fixed to the printed circuit board 20, thereby causing a relative positional shift between the lens unit 36 and the photoelectric conversion element 70 due to thermal expansion in a high temperature environment. It becomes possible to keep it smaller.

  In the first to fourth embodiments, the inner cover members 90 and 190 and the outer cover members 40, 40A, and 140 have been described with reference to the stainless steel material, but may be a ceramic material other than the metal material. . Specifically, materials such as SiC and alumina (Al2O3) can be used. In particular, alumina (Al 2 O 3) has high hardness and a linear expansion coefficient of approximately 7.1 × 10 −6 / ° C., and it is possible to suppress thermal expansion of the lens unit 36 and the like in a high temperature environment. Because there is.

  The present embodiment relates to an optical waveguide holding member and an optical transceiver. Specifically, FIG. 14 shows an optical waveguide holding member in this embodiment. The configuration of the optical waveguide holding member 330 is such that an optical signal incident from an optical fiber is incident, and an optical signal incident on the incident portion 332 is guided to a photoelectric conversion element mounted on a printed circuit board to be described later. The optical waveguide 334 formed in a curved surface, a lens unit 336 that emits an optical signal that has passed through the optical waveguide 334 to a light emitting / receiving unit of the photoelectric conversion element, and a housing unit 304 for fixing them. . The incident portion 332, the optical waveguide 334, and the lens portion 336 are formed of a resin material, and the housing portion 304 is formed of a metal material.

  Specifically, description will be made based on FIGS. 15 and 16. FIG. 15 is a longitudinal sectional view showing an optical waveguide holding member and an optical transceiver in the present embodiment. FIG. 16 is a perspective view showing an assembled state of the optical waveguide holding member and the printed board.

  As shown in FIGS. 15 and 16, the optical transceiver 310 is formed by mounting an optical waveguide holding member 330 on a printed circuit board 320. The lower part of the optical waveguide holding member 330 is fixed on the printed circuit board 320 by an adhesive 322 (shown in a satin pattern in FIG. 16). Although other electronic components are also mounted on the printed circuit board 320, their illustration and description are omitted here.

  In the present embodiment, the optical waveguide 334 and the core portion 334a are formed of an ultraviolet curable epoxy resin, and the core portion 334a is inserted into the groove of the optical waveguide 334. Further, the number of core portions 334a is appropriately selected, and in this embodiment, four core portions 334a are provided in parallel at two locations.

  As shown in FIGS. 15 and 16, the incident portion 332 is provided on the back surface 331 side of the optical waveguide holding member 330 so that an optical fiber connector drawn from a direction parallel to the upper surface of the printed circuit board 320 can be easily connected. ing.

  Further, the plurality of core portions 334 a are formed so as to be connected to the lens portion 336 on the lower surface side of the optical waveguide holding member 330 from the incident portion 332 on the back side of the optical waveguide holding member 330 along the curved surface of the optical waveguide 334. ing. The optical signal transmitted through the optical fiber is transmitted along the core portion 334 a and emitted from the lens portion 336 in the hanging direction, and is output to the photoelectric conversion element 370 on the printed circuit board 320 disposed below the lens portion 336. To reach.

  As shown in FIG. 17, the lens portion 336 is provided on the lower surface side of the optical waveguide holding member 330 that faces the printed board 320. Further, the lens unit 336 has a plurality of light emitting and receiving units 372 (see FIG. 18) of the photoelectric conversion element 370 that irradiates the optical signal that has passed through the core unit 334a at positions corresponding to the core unit 334a of the optical waveguide 334. A spherical lens 336a is provided.

  As shown in FIG. 18, the photoelectric conversion element 370 is mounted at a predetermined position on the printed circuit board 320 so that the plurality of light emitting / receiving units 372 are positioned to face the plurality of spherical lenses 336 a of the lens unit 336. Yes.

  Further, as shown in FIGS. 15 and 16, the housing 304 in the optical waveguide holding member 330 protrudes upward from the left and right sides of the optical waveguide 334 and the front of the optical waveguide 334. A front mounting portion 339.

  In this embodiment, the incident portion 332, the optical waveguide 334, and the lens portion 336 are molded from an olefin resin having a function as a cladding material. Therefore, since the incident portion 332, the optical waveguide 334, and the lens portion 336 are molded of a resin material, the linear expansion coefficient is approximately 70 × 10 −6 / ° C.

  Since the printed circuit board 320 on which the optical waveguide holding member 330 is mounted is formed of glass epoxy resin, the linear expansion coefficient is 13 × 10 −6 / ° C. Therefore, when the thermal expansion accompanying the temperature rise occurs between the printed circuit board 320 and the incident portion 332, the optical waveguide 334, and the lens portion 336, a relative positional shift based on the difference in the linear expansion coefficient occurs.

  The casing 304 is processed with a metal material such as stainless steel (SUS304) and has sufficiently higher rigidity than the resin material. The linear expansion coefficient in the casing 304 is approximately 10.4 × 10 −6 / ° C., which is a value close to the linear expansion coefficient of the printed circuit board 320 (glass epoxy resin). Therefore, the difference in thermal expansion between the housing unit 304 and the printed circuit board 320 is set to be small. For this reason, the material constituting the housing unit 304 needs to be a material having a value that is at least smaller than the linear expansion coefficient of the resin material, and is a material that is close to the linear expansion coefficient of the printed circuit board 320. It is desirable that

  The optical waveguide holding member 330 is made of a metal material having a higher rigidity than the resin material of the housing 304 and the lower part is fixed to the printed circuit board 320 by the adhesive 322, so that the temperature is higher than normal temperature (25 ° C.). When the atmosphere is used, the thermal expansion in the X direction and the Y direction of the resin material forming the optical waveguide holding member 330 is restrained by the casing unit 304.

  The casing 304 is formed by, for example, a method of forming a recess 380 corresponding to the outer shape of the optical waveguide holding member 330 by pressing a stainless steel plate, or by injecting a molten stainless steel into a mold or a die-cast mold. Then, it is processed by either a method of manufacturing by casting or a method of cutting and manufacturing a metal block made of stainless steel. In addition, when manufacturing the housing | casing part 304 by casting, since thickness can be changed suitably, it becomes possible to increase the thickness of the location where the stress of thermal expansion acts, and it is stronger. It is possible to restrain the linear expansion of the resin material.

  Thus, the housing | casing part 304 can restrain the thermal expansion which goes to the outer side of the X direction of a resin material, and a Y direction. For this reason, the relative positional deviation between the lens portion 336 provided on the lower surface side of the optical waveguide holding member 330 and the photoelectric conversion element 370 mounted on the printed circuit board 20 is restricted, and the optical signal can be transmitted and received. Can be suppressed.

  According to the optical transceiver 310 configured as described above, since it is not necessary to use a nerve in the temperature environment during the assembly process, the production efficiency of the optical transceiver 310 can be increased, the yield can be improved, and the production can be performed. Improves.

Next, a manufacturing method of the optical waveguide holding member 330 in the present embodiment will be described.
As described above, the housing portion 304 in the optical waveguide holding member 330 is formed of a metal material, and the incident portion 332, the optical waveguide 334, and the lens portion 336 are formed of a resin material.

  First, after the housing portion 304 made of a metal material is manufactured, an incident portion 332, an optical waveguide 334, and a lens portion 336 are formed by pouring and hardening a resin material into a mold. Specifically, a description will be given with reference to FIGS. 19, 20, and 21. FIG. 19 is a perspective view of the whole for explaining the manufacturing method, FIG. 19A is a perspective view in the front direction, and FIG. 19B is a perspective view in the rear direction. 20 and 21 are perspective views of a main part.

  As shown in FIGS. 19A and 19B, the casing 304 is put into molds 350a and 350b having a shape in which the casing 304 can be accommodated. Note that nothing is formed in the portion where the incident portion 332, the optical waveguide 334, and the lens portion 336 are formed in the housing portion 304.

  Thereafter, the molds 350a and 350b are combined, and the resin is poured from the resin filling port in the molds 350a and 350b. After pouring the resin into the whole, the resin is solidified, and then the molds 350a and 350b are removed to complete the optical waveguide holding member 330 in the present embodiment.

  19A and 19B show a case where a portion made of a resin material formed with the housing portion 304, that is, the housing portion 403, and the portions of the incident portion 332, the optical waveguide 334, and the lens portion 336 are disassembled. Is shown.

  FIG. 20A shows the optical waveguide holding member 330 to be manufactured. The upper side is a top view of the optical waveguide holding member 330, and the lower side is a side view of the optical waveguide holding member 330. FIG. 20B shows a perspective view of the optical waveguide holding member 330 in which a portion cut along a broken line 20A-20B is manufactured. In a state in which the casing 304 is sandwiched between the molds 350a and 350b, a space is generated between the casing 304 and the molds 350a and 350b. The resin material flows into this space as a resin flow path, and fills the entire space with the resin material. FIG. 20C is an enlarged perspective view of the resin flow path.

  Similarly, FIG. 21A shows the optical waveguide holding member 330 to be manufactured. The upper side is a top view of the optical waveguide holding member 330 and the lower side is a side view of the optical waveguide holding member 330. FIG. 21 (b) shows a perspective view of the optical waveguide holding member 330 in which the portion cut along the broken line 21A-21B is manufactured. In a state in which the casing 304 is sandwiched between the molds 350a and 350b, a space is generated between the casing 304 and the molds 350a and 350b. The resin material flows into this space as a resin flow path, and fills the entire space with the resin material. FIG. 21C is an enlarged perspective view of the resin flow path portion.

  Thus, the optical waveguide holding member and the optical transceiver in the present embodiment are manufactured.

  In the present embodiment, the method of connecting the printed circuit board 320 and the casing unit 304 with an adhesive has been described. However, as shown in FIG. 22, the printed circuit board 320 and the casing unit 304 are connected by press fitting. Or a method of connecting by soldering. The method of connecting by press-fit is to form the press-fit terminal 402 in advance when forming the casing portion 304 and connect by the press-fit terminal 402 when connecting to the printed circuit board 320. In addition, a method of connecting by soldering is to form a solder joint terminal 404 when forming the housing portion 304 in advance, and solder the solder joint terminal 404 with the solder 406 when connecting to the printed circuit board 320. This is what makes the connection. In these methods, since it is possible to attach to the printed circuit board 320 more firmly than the adhesive, the thermal expansion of the resin material can be further suppressed, and the positional deviation of the optical axis can be suppressed.

  In this embodiment, the case 304 is made of a stainless steel material, but the case 304 may be a ceramic material other than the metal material. Specifically, materials such as SiC and alumina (Al2O3) can be used. In particular, alumina (Al 2 O 3) has high hardness and a linear expansion coefficient of approximately 7.1 × 10 −6 / ° C., and constitutes the incident portion 332, the optical waveguide 334, and the lens portion 336 in a high temperature environment. This is because it is possible to suppress the thermal expansion of the resin material.

  The present embodiment relates to an optical waveguide holding member and an optical transceiver in which the housing portion 404 is formed of a thermoplastic resin material or a thermosetting resin material. FIG. 23 shows this embodiment. The optical waveguide holding member 430 in the present embodiment is different from a thermoplastic resin material or a casing 404 made of a thermosetting resin material, and a thermoplastic resin material or a thermosetting resin material constituting the casing 404. It consists of an incident portion 432 made of a resin material, an optical waveguide 434, and a lens portion 436. Note that the linear expansion coefficient in the thermoplastic resin material or thermosetting resin material constituting the housing portion 404 is smaller than the linear expansion coefficient of the resin material constituting the incident portion 432, the optical waveguide 434, and the lens portion 436. Therefore, a value close to the linear expansion coefficient of a printed circuit board (not shown) to be attached is desirable.

  When the casing 404 is formed of a thermoplastic resin material, the casing 404 is formed by a method such as injection molding, and the casing 404 thus formed is similar to the case of the fifth embodiment. The resin material is poured into a mold and solidified. Thus, the method of forming using two types of resin materials is called double molding or two-color molding.

  On the other hand, when the casing 404 is formed of a thermosetting resin material, the casing 404 is formed by a method such as cast molding or transfer molding. In the casing 404 thus formed, As in the case of Example 5, the resin material is poured into a mold and solidified.

  The optical waveguide holding member 430 in the present embodiment is bonded to the substrate with an adhesive.

  In the above embodiment, when the outer cover members 40 and 140 and the inner cover members 90 and 190 have shapes corresponding to the outer shape and the inner shape of the optical waveguide holding member 30, The description is given by exemplifying what is configured not to be compressed. However, the present invention is not limited to this, and for example, a portion that suppresses a portion in which thermal expansion in the X direction and the Y direction occurs (a portion in which thermal expansion appears significantly). Needless to say, the optical waveguide holding member 30 may be shaped so as to be in close contact with the surface.

  Moreover, in the said Example, although the case where the outer side cover members 40 and 140 and the inner side cover members 90 and 190 were integrally formed was demonstrated as an example, it is not restricted to this, The surface shape of the optical waveguide holding member 30 ( For example, the outer cover members 40 and 140 and the inner cover members 90 and 190 may be divided into two parts in the left-right direction (X direction) or the up-down direction (Z direction) according to the presence / absence of unevenness, and may be combined at the time of assembly. Of course.

  In the above embodiment, the case where the outer cover members 40 and 140 and the inner cover members 90 and 190 are formed of stainless steel has been described. However, if the material has a linear expansion coefficient similar to that of the printed circuit board 20, stainless steel is used. Of course, other metal materials or ceramic materials may be used.

  In the above embodiment, the case 304 is made of stainless steel. However, any material having a linear expansion coefficient similar to that of the printed circuit board 320 may be made of a metal material other than stainless steel or a ceramic material. It may be formed.

1 is a longitudinal sectional view showing a first embodiment of an optical waveguide holding member and an optical transceiver according to the present invention. The perspective view which shows the assembly | attachment state of an outer side cover member (it shows with a dashed-dotted line), an optical waveguide holding member, and a printed circuit board The disassembled perspective view which shows the state before the assembly which isolate | separated the outer side cover member from the optical waveguide holding member of Example 1. FIG. The perspective view which shows the structure of the lens part distribute | arranged to the lower surface side of the optical waveguide holding member The perspective view which shows the photoelectric conversion element 70 mounted in the upper surface of a printed circuit board. FIG. 3 is a longitudinal sectional view showing an optical transceiver according to a second embodiment. The disassembled perspective view which shows the state before the assembly which isolate | separated the optical waveguide holding member and inner side cover member of Example 2. FIG. FIG. 6 is a longitudinal sectional view showing an optical transceiver according to a third embodiment. The disassembled perspective view which shows the state before the assembly which isolate | separated the optical waveguide holding member of Example 3, the outer side cover member, and the inner side cover member. FIG. 5 is a longitudinal sectional view showing an optical transceiver according to a fourth embodiment. The disassembled perspective view which shows the state before the assembly which isolate | separated the optical waveguide holding member of Example 4, the outer side cover member, and the inner side cover member. The perspective view for demonstrating the modification 1 Longitudinal sectional view for explaining Modification 2 Vertical sectional view showing an optical waveguide holding member in Example 5 Vertical sectional view of optical waveguide holding member and optical transceiver in Example 5 The perspective view which shows the assembly | attachment state of the optical waveguide holding member in Example 5, and a printed circuit board. The perspective view which shows the structure of the lens part distribute | arranged to the lower surface side of the optical waveguide holding member in Example 5 The perspective view which shows the photoelectric conversion element mounted in the upper surface of the printed circuit board in Example 5. FIG. Manufacturing process explanatory drawing of the optical waveguide holding member in Example 5 Manufacturing process explanatory drawing in the principal part of the optical waveguide holding member in Example 5 (1) Manufacturing process explanatory drawing in the principal part of the optical waveguide holding member in Example 5 (2) Explanatory drawing of another attachment method of the optical waveguide holding member in Example 5 A longitudinal sectional view showing an optical waveguide holding member in Example 6

10, 10A, 10B, 10C Optical transceiver 20 Printed circuit board 22 Adhesive 30 Optical waveguide holding member 40, 40A, 140 Outer cover member 41 Back surface 41a First opening 44a Slit 32 Incident part 34 Optical waveguide 34a Core part 36 Lens part 60 Recess 70 Photoelectric conversion element 72 Light emitting / receiving portion 80 Recess 90, 190 Inner cover member 92 Horizontal extension 92a Second opening 100, 120 Fixing end 110 Solder 123, 126 Through hole 124 Conductive pattern 200, 210 Relief

Claims (15)

An incident portion into which an optical signal from an optical fiber is incident, an optical waveguide formed in a curved shape so as to guide the optical signal incident on the incident portion to a photoelectric conversion element mounted on a printed circuit board, and the light An optical device having a lens unit that emits an optical signal that has passed through the waveguide to the light emitting and receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing unit for fixing each of the lens units. In the waveguide holding member,
The incident portion, the waveguide, and the lens portion are made of a resin material, and the housing portion is made of a metal material or a ceramic material. The optical waveguide holding member according to claim 1,
An optical waveguide holding member, wherein a linear expansion coefficient of a metal material or a ceramic material forming the housing portion is lower than a linear expansion coefficient of the resin material. The optical waveguide holding member according to claim 1 or 2,
The optical waveguide holding member, wherein the casing is formed by pressing, casting, or cutting. The optical waveguide holding member according to any one of claims 1 to 3,
The optical waveguide holding member, wherein the incident portion, the waveguide, and the lens portion are formed by insert molding in the formed casing portion. The optical waveguide holding member according to any one of claims 1 to 4,
The optical waveguide holding member, wherein the casing is made of a stainless material. An incident portion into which an optical signal from an optical fiber is incident, an optical waveguide formed in a curved shape so as to guide the optical signal incident on the incident portion to a photoelectric conversion element mounted on a printed circuit board, and the light An optical device having a lens unit that emits an optical signal that has passed through the waveguide to the light emitting and receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing unit for fixing each of the lens units. In the waveguide holding member,
The incident portion, the waveguide, and the lens portion are made of a resin material, and the casing portion is made of a thermoplastic resin material different from the resin material. Element. The optical waveguide holding member according to claim 6,
The optical waveguide holding member, wherein a linear expansion coefficient of a thermoplastic resin material forming the casing is lower than a linear expansion coefficient of the resin material. The optical waveguide holding member according to claim 6 or 7,
The optical waveguide holding member, wherein the casing is formed by injection molding. The optical waveguide holding member according to any one of claims 6 to 8,
The optical waveguide holding member, wherein the incident portion, the waveguide, and the lens portion are formed by double-molding or two-color molding of a resin material in the formed casing portion. . An incident portion into which an optical signal from an optical fiber is incident, an optical waveguide formed in a curved shape so as to guide the optical signal incident on the incident portion to a photoelectric conversion element mounted on a printed circuit board, and the light An optical device having a lens unit that emits an optical signal that has passed through the waveguide to the light emitting and receiving unit of the photoelectric conversion element, the incident unit, the optical waveguide, and a housing unit for fixing each of the lens units. In the waveguide holding member,
The incident portion, the waveguide, and the lens portion are formed of a resin material, and the casing is formed of a thermosetting resin material different from the resin material. Holding member. The optical waveguide holding member according to claim 10,
The optical waveguide holding member, wherein a linear expansion coefficient of a thermosetting resin material forming the housing portion is lower than a linear expansion coefficient of the resin material. The optical waveguide holding member according to claim 10 or 11,
The optical waveguide holding member, wherein the casing is formed by casting or transfer molding. The optical waveguide holding member according to any one of claims 10 to 12,
The optical waveguide holding member, wherein the incident portion, the waveguide, and the lens portion are formed by double-molding or two-color molding of a resin material in the formed casing portion. .   6. An optical transceiver comprising the optical waveguide holding member according to claim 1 fixed to a printed circuit board by an adhesive, a press fit, or soldering.   14. An optical transceiver comprising the optical waveguide holding member according to claim 6 fixed to a printed circuit board with an adhesive.

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