JP2011090176A - Photoelectric conversion module and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion module and a method of manufacturing the same having a high yield and reliability. <P>SOLUTION: The photoelectric conversion module includes: a ferrule 12 having an optical fiber insert hole 21 in which a glass fiber 16 is inserted; an electrode 13 provided on a device mounting surface 12a at the front side in the direction of inserting the glass fiber 16 in the ferrule 12; an optical device 14 fitted to the device mounting surface 12a of the ferrule 12 in a state of conductively being connected to an electrode 13; and an under fill material 41 for fixing a mounting portion of the optical device 14 to the ferrule 12. The under fill material 41 is formed of translucent resin, and a part thereof is made to be a protective part 42 interposed in a position of the optical device 14 facing the optical fiber insert hole 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion module used for optical transmission and the like and a manufacturing method thereof.

Opto-electric conversion modules that transmit optical signals generated by light-emitting elements through optical fibers and optical transmissions that receive optical signals that have propagated through optical fibers by light-receiving elements are expected to be compact due to restrictions on storage space. It is rare.
For this reason, an optical fiber is inserted and fixed in a fiber hole formed in a resin ferrule having a metal plating portion on the outer surface, and different devices such as an optical device and an electric device are electrically connected to each other through the metal plating portion. There has been known a technique for making the connection compact so as to be connectable (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-115284

In general, the photoelectric conversion module inserts an optical fiber into the optical fiber insertion hole, and further fixes the mounting location of the optical device to the ferrule with the optical device mounted on the substrate or afterwards with an underfill material. is doing.
In such a fixing structure, the end of the optical fiber may be fixed in contact with the optical device, and the optical device may be damaged by contact with the end of the optical fiber, thereby impairing long-term reliability. .
For example, when the underfill material is cured while the end of the optical fiber is in contact with the optical device, the optical fiber and the optical device are relatively displaced at the contact location due to shrinkage force when the underfill material is cured, etc. There is a high risk that the element portion of the optical device will be damaged, leading to a decrease in yield.

  An object of the present invention is to provide a photoelectric conversion module with high yield and reliability, and a manufacturing method thereof.

The photoelectric conversion module of the present invention capable of solving the above-mentioned problems is a ferrule having an optical fiber insertion hole through which an optical fiber is inserted,
An electrode provided on the mounting surface on the front side in the insertion direction of the optical fiber in the ferrule;
An optical device attached to the mounting surface of the ferrule in a conductive connection with the electrode;
A fixing material for fixing the mounting position of the optical device to the ferrule,
The fixing material is formed of a resin having translucency, and a part of the fixing material serves as a protective portion interposed at a position facing the optical fiber insertion hole of the optical device.

  Moreover, the photoelectric conversion module of this invention WHEREIN: It is preferable that the said protection part is inclined with respect to the orthogonal plane with the axial direction of the said optical fiber insertion hole.

  Moreover, the photoelectric conversion module of this invention WHEREIN: It is preferable that the said protection part is provided with the anti-reflective film in the surface at the side of the said optical fiber insertion hole.

  In the photoelectric conversion module of the present invention, it is preferable that a part of the electrode is exposed from the fixing material.

  In the photoelectric conversion module of the present invention, it is preferable that the periphery of the fixing material is covered with a case made of a heat conductive material.

  In the photoelectric conversion module of the present invention, it is preferable that an electric device is attached to the case.

In the method for manufacturing the photoelectric conversion module of the present invention, the optical device is conductively connected to the electrode provided on the mounting surface on the front side in the optical fiber insertion direction in the ferrule having the optical fiber insertion hole through which the optical fiber is inserted. Optical device mounting process to be mounted,
In the case where a fixing material made of a light-transmitting resin is filled in a molten state, the fixing surface is inserted so that the fixing material is interposed at a position facing the optical fiber insertion hole. And a molding step of curing the material.

  Moreover, in the manufacturing method of the photoelectric conversion module of this invention, it is preferable that the said ferrule inclines by a predetermined angle with respect to a perpendicular direction in the said formation process, and puts it in the said case.

  Moreover, in the manufacturing method of the photoelectric conversion module of this invention, after the said formation process, it is preferable to take out the said fixed material which hardened | cured from the said case.

  In the method of manufacturing an optical / electrical conversion module of the present invention, it is preferable that the case is made of a heat conductive material, and an electric device is attached to the case after the fixing material is cured.

According to the photoelectric conversion module of the present invention, even if an optical fiber is inserted into the optical fiber insertion hole, the optical fiber insertion hole of the optical device comprises a part of the fixing material that fixes the mounting position of the optical device to the ferrule. Interference of the end of the optical fiber to the optical device is prevented by the protective portion interposed at the position facing the optical fiber. Thereby, damage to the optical device can be prevented, yield can be increased, and high reliability can be maintained over a long period of time. In addition, since the optical fiber can be inserted and connected to the optical fiber insertion hole after being attached to the circuit board or the like, compared to the structure in which the optical fiber is previously connected to the ferrule, In addition, good handleability can be ensured.
In addition, according to the method for manufacturing the photoelectric conversion module of the present invention, the interference of the optical fiber end with the optical device can be prevented, and a photoelectric conversion module with high yield and reliability can be easily manufactured.

It is sectional drawing of the photoelectric conversion module which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the photoelectric conversion module of FIG. 1 fixed to the circuit board. It is a figure explaining the manufacturing method of a photoelectric conversion module, Comprising: (a)-(c) is sectional drawing, respectively. It is sectional drawing of the photoelectric conversion module which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the photoelectric conversion module of FIG. 4 fixed to the circuit board. It is a figure explaining the manufacturing method of a photoelectric conversion module, Comprising: (a), (b) is sectional drawing, respectively.

Hereinafter, an example of an embodiment of a photoelectric conversion module and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
(First embodiment)
First, the photoelectric conversion module and the manufacturing method thereof according to the first embodiment will be described.
As shown in FIGS. 1 and 2, the photoelectric conversion module 11 according to the first embodiment includes a ferrule 12, an electrode 13, an optical device 14, and an underfill material (fixing material) 41.
The ferrule 12 is molded from a resin or the like, and has an optical fiber insertion hole 21 into which a glass fiber (optical fiber) 16 exposed from the end of the optical fiber core wire is inserted from the rear end side.

  The electrode 13 is provided on the device mounting surface (mounting surface) 12a on the front side in the insertion direction of the glass fiber 16 in the ferrule 12. For example, the electrode 13 is integrally provided on the device mounting surface 12a of the ferrule 12 by insert molding. ing. The ferrule 12 is integrally formed with a plurality of electrodes 13.

The optical device 14 has an element portion 31 and a terminal portion 32 on an element surface 14a that is an attachment surface attached to the device mounting surface 12a.
The optical device 14 is, for example, a light emitting element or a light receiving element such as a VCSEL (Vertical Cavity Surface Emitting Laser) or a photodiode. The element unit 31 of the optical device 14 is a light emitting unit when the optical device 14 is a light emitting element, and is a light receiving unit when the optical device 14 is a light receiving element.

In the optical device 14, the terminal portion 32 is electrically connected to the electrode 13 provided on the ferrule 12 by, for example, a bump 30 made of gold (Au). The connection by the bump 30 is performed by flip chip connection in which the bump 30 is melted by ultrasonic vibration or heat to connect the terminal portion 32 and the electrode 13.
Thus, the optical device 14 attached to the ferrule 12 has the element portion 31 disposed at a position facing the optical fiber insertion hole 21 of the ferrule 12.

  The optical device 14 is entirely covered with the underfill material 41 including the attachment portion with the ferrule 12 and is fixed by the underfill material 41. The underfill material 41 is formed from a resin having translucency, and a part of the underfill material 41 is interposed at a position facing the optical fiber insertion hole 21 in the element surface 14 a of the optical device 14 to serve as a protection portion 42. Yes. The protective portion 42 of the underfill material 41 has an inclined surface 42 a that is inclined with respect to a plane orthogonal to the axial direction of the optical fiber insertion hole 21. As the underfill material 41, a fixing epoxy resin (for example, Epoxy-Tek353ND manufactured by Epoxy Technology) or the like can be used.

Thus, since the protection part 42 has the inclined surface 42a inclined with respect to the surface orthogonal to the axial direction of the optical fiber insertion hole 21, reflection of light from the glass fiber 16 can be prevented. , Light can be transmitted satisfactorily.
The inclined surface 42a preferably has an inclination angle θ of about 8 ° to 12 ° with respect to a surface orthogonal to the axial direction of the optical fiber insertion hole 21.

  In addition, the protective portion 42 of the underfill material 41 is provided with an antireflection film 45 on an inclined surface 42 a that is a surface on the optical fiber insertion hole 21 side. The antireflection film 45 is formed from a resin film having translucency and elasticity. By providing this antireflection film 45 on the inclined surface 42a of the protection part 42, reflection of light from the glass fiber 16 can be further prevented. In addition, when the light is transmitted from the optical device 14 to the glass fiber 16, the reflection of light can be prevented by the antireflection film 45.

  The underfill material 41 is formed so as to be inclined as a whole, whereby a part of the electrode 13 of the ferrule 12 is exposed from the underfill material 41 to form an electrode terminal 13a. Thereby, it is possible to easily wire the electrode terminal 13a of the electrode 13 of the ferrule 12 by wire bonding.

The photoelectric conversion module 11 having the above structure is fixed to an end portion of the circuit board 52 on which the electric device 51 is mounted. A circuit pattern (not shown) is formed on the circuit board 52, and the terminal 51a of the electric device 51 is electrically connected to the circuit pattern.
The terminal 51a of the electric device 51 mounted on the circuit board 52 is electrically connected to the electrode terminal 13a of the ferrule 12 by a bonding wire 53 made of, for example, gold (Au).

  On the upper surface of the ferrule 12 on which the electrode terminal 13a is formed, it is preferable to make the protruding dimension of the underfill material 41 as small as possible. Thus, if the protrusion dimension of the underfill material 41 from the upper surface of the ferrule 12 is reduced, wire bonding between the terminal 51a of the electrical device 51 and the electrode terminal 13a of the ferrule 12 can be facilitated, and bonding The length of the wire 53 can be shortened to suppress the influence of electrical noise as much as possible.

The electrical device 51 is, for example, an optical element driving IC such as a driver or a transimpedance amplifier.
Further, the fixing portion between the circuit board 52 and the photoelectric module 11 is covered with a resin 54 by being potted.

  As described above, the glass fiber 16 is inserted and held in the optical fiber insertion hole 21 from the rear end side of the photoelectric conversion module 11 fixed to the circuit board 52. The glass fiber 16 inserted into the optical fiber insertion hole 21 is composed of a core 16a and a clad 16b, and its end surface is inclined at substantially the same angle as the inclined surface 42a of the protection part 42, whereby the protection part It is in close contact with the antireflection film 45 provided on the inclined surface 42a of 42. Therefore, also when light is transmitted from the optical device 14 to the glass fiber 16, reflection of light at the end face of the glass fiber 16 is prevented, and good light transmission is performed.

In the photoelectric conversion module 11 described above, optical transmission is performed between the optical device 14 and the glass fiber 16.
When light is transmitted from the optical device 14 made of a light emitting element to the glass fiber 16, the light emitted from the element portion 31 of the optical device 14 enters the core 16 a of the glass fiber 16 through the antireflection film 45.
When light is transmitted from the glass fiber 16 to the optical device 14 including a light receiving element, light emitted from the core 16 a of the glass fiber 16 enters the element portion 31 of the optical device 14 through the antireflection film 45. .

  According to the photoelectric conversion module according to the first embodiment, even if the glass fiber 16 is inserted into the optical fiber insertion hole 21, a part of the underfill material 41 that fixes the mounting position of the optical device 14 to the ferrule 12. The interference of the end portion of the glass fiber 16 to the optical device 14 is prevented by the protective portion 42 interposed at the position facing the optical fiber insertion hole 21 of the optical device 14. Thereby, damage to the element part 31 of the optical device 14 can be prevented, and the yield can be increased and high reliability can be maintained over a long period of time. Moreover, since the glass fiber 16 can be inserted and connected to the optical fiber insertion hole 21 after being attached to the circuit board 52, compared to the structure in which the glass fiber 16 is connected in advance, the glass fiber 16 can be attached to the circuit board 52. In this case, good handleability can be ensured.

  Next, a case where the photoelectric conversion module 11 is manufactured will be described for each process.

(Optical device mounting process)
As shown in FIG. 3A, first, the optical device 14 is mounted on the device mounting surface 12 a of the ferrule 12. Specifically, the bump 30 between the electrode 13 on the device mounting surface 12a and the terminal portion 32 of the optical device 14 is melted by ultrasonic vibration or heat, and the terminal portion 32 and the electrode 13 are electrically connected.

(Molding process)
Next, as shown in FIG. 3B, the case 55 is filled with a molten resin to be the underfill material 41, and the device mounting surface of the ferrule 12 on which the optical device 14 is mounted in the case 55. Insert the 12a side.
At this time, the ferrule 12 is put into the case 55 so that the molten resin enters the position facing the optical fiber insertion hole 21 of the ferrule 12.
Further, the ferrule 12 placed in the case 55 is tilted by about 8 ° to 12 ° with respect to the vertical direction, and a part of the electrode 13 is exposed from the underfill material 41, and the underfill material 41 is cured in its posture. Keep up.

Thereby, the protection part 42 which has the inclined surface 42a can be easily formed in the position which faces the optical fiber penetration hole 21 of the optical device 14, and the electrode terminal 13a with which wire bonding is easy can be provided.
Moreover, the thickness of the protection part 42 can be easily adjusted by adjusting the moving distance of the ferrule 12 in the vertical direction. Thereby, the optical coupling efficiency of the photoelectric conversion module 61 can be managed as designed.

  When the underfill material 41 is cured, the cured underfill material 41 is taken out from the case 55 and the antireflection film 45 is inserted into the optical fiber insertion hole 21 from the rear end side.

  And according to said manufacturing method, the photoelectric conversion module 11 by which the attachment location of the optical device 14 of the ferrule 12 was covered and fixed by the underfill material 41 is obtained. That is, according to the above-described manufacturing method of the photoelectric conversion module, the interference of the end of the glass fiber 16 to the optical device 14 is prevented, and the photoelectric conversion module 11 with high yield and reliability can be easily manufactured. it can.

(Second Embodiment)
Next, the photoelectric conversion module and the manufacturing method thereof according to the second embodiment will be described.
In addition, the same component as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.
As shown in FIGS. 4 and 5, the photoelectric conversion module 61 according to the second embodiment has a structure in which the periphery of the underfill material 41 is covered with a case 62. The case 62 is made of a material having heat conductivity and conductivity, such as aluminum.

  In the photoelectric conversion module 61, the electric device 51 is attached to one side surface of the case 62. The electrical device 51 attached to the case 62 has a terminal 51a electrically connected to the electrode terminal 13a of the ferrule 12 and the circuit pattern of the circuit board 52 by a bonding wire 53 made of, for example, gold (Au).

Thus, according to the photoelectric conversion module 61 having a structure in which the periphery of the underfill material 41 is covered by the case 62 formed of a heat conductive material, the case 62 serves as a heat sink, and a good heat dissipation effect can be obtained. In particular, it is possible to effectively dissipate heat from the electrical device 51 attached to the case 62 and to function with good performance over a long period of time.
Moreover, since the electrical device 15 is attached in the vicinity of the optical device 14, the length of the bonding wire 53 can be shortened as much as possible, and the generation of electrical noise can be reduced.

When manufacturing the photoelectric conversion module 61, as shown in FIG. 6A, in the molding process, a molten resin that becomes the underfill material 41 is placed in a case 62 formed of a heat conductive material. In this case 62, the device mounting surface 12 a side of the ferrule 12 on which the optical device 14 is mounted is placed and tilted.
After that, when the underfill material 41 is cured, as shown in FIG. 6B, the electric device 51 is attached to one side surface of the case 62, and the terminal 51 a is conductively connected to the electrode terminal 13 a of the ferrule 12 by the bonding wire 53.

  In the above embodiment, the case where the photoelectric conversion modules 11 and 61 are fixed to the end portion of the circuit board 52 has been described as an example. However, the photoelectric conversion modules 11 and 61 are mounted on the surface of the circuit board 52. May be. In that case, the photoelectric modules 11 and 61 are bonded and fixed to the circuit board 52 (die bonding), and the electrodes 13 of the ferrule 12 are conductively connected to the circuit pattern of the circuit board 52 by reflow or wire bonding. .

11, 61: photoelectric conversion module, 12: ferrule, 12a: device mounting surface (mounting surface), 13: electrode, 14: optical device, 16: glass fiber (optical fiber), 21: optical fiber insertion hole, 41: Underfill material (fixing material), 42: protection part, 45: antireflection film, 51: electrical device, 55, 62: case

Claims (10)

A ferrule having an optical fiber insertion hole into which an optical fiber is inserted;
An electrode provided on the mounting surface on the front side in the insertion direction of the optical fiber in the ferrule;
An optical device attached to the mounting surface of the ferrule in a conductive connection with the electrode;
A fixing material for fixing the mounting position of the optical device to the ferrule,
The photoelectric conversion module according to claim 1, wherein the fixing member is made of a resin having translucency, and a part of the fixing member serves as a protection portion that is interposed at a position facing the optical fiber insertion hole of the optical device. The photoelectric conversion module according to claim 1,
The photoelectric conversion module, wherein the protection part is inclined with respect to a plane perpendicular to the axial direction of the optical fiber insertion hole. The photoelectric conversion module according to claim 1 or 2,
The photoelectric conversion module according to claim 1, wherein the protective part is provided with an antireflection film on a surface on the optical fiber insertion hole side. The photoelectric conversion module according to any one of claims 1 to 3,
A part of the electrode is exposed from the fixing material. The photoelectric conversion module according to any one of claims 1 to 3,
The photoelectric conversion module, wherein the fixing material is covered with a case made of a heat conductive material. The photoelectric conversion module according to claim 5,
An electrical / electrical conversion module, wherein an electrical device is attached to the case. An optical device mounting step in which the optical device is conductively connected to an electrode provided on a mounting surface on the front side in the optical fiber insertion direction in a ferrule having an optical fiber insertion hole into which the optical fiber is inserted; and
In the case where a fixing material made of a light-transmitting resin is filled in a molten state, the fixing surface is inserted so that the fixing material is interposed at a position facing the optical fiber insertion hole. The manufacturing method of the photoelectric conversion module characterized by including the shaping | molding process which hardens a material. It is a manufacturing method of the photoelectric conversion module according to claim 7,
In the molding step, the ferrule is tilted by a predetermined angle with respect to a vertical direction and is put into the case. It is a manufacturing method of the photoelectric conversion module according to claim 7 or 8,
A method of manufacturing an optical / electrical conversion module, wherein the cured fixing material is taken out of the case after the molding step. It is a manufacturing method of the photoelectric conversion module according to claim 7 or 8,
The method for manufacturing a photoelectric conversion module, wherein the case is made of a heat conductive material, and an electric device is attached to the case after the fixing material is cured.

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