JP3592492B2 - Optical module and method of manufacturing the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical module and a method of manufacturing the same, and more particularly to a passive alignment type optical module in which a semiconductor laser device and an optical fiber are optically coupled using a substrate (a quartz-based platform or the like) having a guide groove for guiding the optical fiber on the surface. A technology that is effective when applied to manufacturing technology.
[0002]
[Prior art]
Optical modules for transmission and reception used in optical fiber transmission systems are required to have high performance and low cost.
[0003]
As one of the optical modules, a substrate (mounting substrate) made of silicon having an optical device mounting portion for fixing a semiconductor laser device on the surface and a guide groove having a V-shaped cross section formed toward the optical device mounting portion is used. 2. Description of the Related Art A passive alignment type optical module that performs assembly by utilizing the same is known.
[0004]
In this optical module, a semiconductor laser element is fixed to an optical element mounting portion of a substrate (mounting substrate, in the case of a silicon substrate, referred to as a silicon platform), and an optical fiber is inserted into the guide groove. Optical coupling is performed without performing optical axis alignment with the laser element (passive alignment).
[0005]
Since the optical axis is determined only by inserting the optical fiber into the guide groove having the V-shaped cross section, the optical fiber is moved and adjusted in the optical axis direction and is fixed to the substrate at a position where the amount of light taken in is the highest.
[0006]
An alignment mark (index mark) is provided on the optical element mounting portion of the substrate. This alignment mark is the same mark as an alignment mark written on an optical element such as a semiconductor laser element or a light receiving element.
[0007]
In fixing the optical element to the optical element mounting portion, the optical element is aligned and fixed to the substrate while detecting the alignment marks on the optical element and the substrate.
[0008]
This type of optical module is described in, for example, "Electronic Materials", July 1997, P65-P69, published by the Industrial Research Institute, "Optronics", July 1996, published by Optronics, P139-P143 and P156-P161. ing.
[0009]
[Problems to be solved by the invention]
In manufacturing an optical module using a silicon platform, alignment marks corresponding to alignment marks provided in advance on optical elements such as a semiconductor laser element and a light receiving element are provided on each optical element mounting portion of the silicon platform, and At the time of fixing, high-precision fixing is performed by aligning the alignment marks.
[0010]
The optical fiber is inserted and fixed in a guide groove provided on the surface of the silicon platform, whereby the optical axis of the optical fiber is aligned with an optical element, for example, a semiconductor laser element.
[0011]
However, it has been clarified by the present inventors that the following problems occur in such a conventional method for manufacturing an optical module.
[0012]
(1) The emission surface of the semiconductor laser device is constituted by a cleavage plane of a crystal, and this cleavage plane is formed by cleaving a crystal substrate. In the cleavage operation, since a part of the crystal substrate is broken by applying an external force, the position of the cleavage plane is not strictly specified, and as a result, the length of the semiconductor laser device (the length of the optical waveguide) is slightly different. Therefore, when the distance between the emission surface of the semiconductor laser device and the tip of the optical fiber changes, the amount of laser light taken into the optical fiber changes.
[0013]
Therefore, in the present applicant, the distance between the emission surface of the semiconductor laser element and the tip of the optical fiber is measured, and a work out of a predetermined distance range is determined as a defective product. Is time-consuming and hinders the reduction of the manufacturing cost of the optical module.
[0014]
(2) The guide groove formed on the surface of the silicon platform is formed by photolithography and etching using a photomask determined with respect to the alignment mark of the optical element mounting portion. In some cases, the formation position of the guide groove may change due to variations in time or manufacturing variations in the photomask to be used. This misalignment causes optical axis misalignment and lowers the manufacturing yield.
[0015]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical module and a method for manufacturing the same, in which the distance between the optical element and the tip of the optical fiber can be easily measured.
[0016]
It is another object of the present invention to provide an optical module capable of fixing an optical element by correcting a positional deviation amount of a guide groove and a method of manufacturing the same.
[0017]
Another object of the present invention is to provide an optical module capable of performing highly accurate optical coupling and a method for manufacturing the same.
[0018]
Another object of the present invention is to provide an optical module and a method for manufacturing the same, which can reduce the manufacturing cost.
[0019]
The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0020]
[Means for Solving the Problems]
The outline of a typical invention among the inventions disclosed in the present application will be briefly described as follows.
[0021]
(1) A substrate having an optical element mounting portion and a guide groove for guiding an optical fiber extending toward the optical element mounting portion on one surface; an optical element fixed to the optical element mounting portion; An optical fiber that is inserted and fixed along and has an end facing the optical element.Provided on one side or both sides,An optical fiber position measurement mark that can measure the amount of positional deviation of the fixed position of the tip of the optical fiberAnd provided in the periphery of the optical element mounting portion, in a length direction of the guide groove and in a direction orthogonal to the guide groove.The amount of displacement of the fixed position of the optical element can be measured and the position measurement mark for the optical fiber andIn a certain positional relationshipAn optical element position measurement markWhen,At one edge or both edges of the guide grooveProvided,The optical element mounting portion;In a certain positional relationshipReference mark for measuring the amount of misalignment of the guide groove in the width direction with the guide grooveHaveYou.
[0022]
The position measurement mark for the optical element and the position measurement mark for the optical fiber have a pitch mark configuration in which a plurality of marks are arranged at a predetermined pitch so that the amount of positional deviation can be calculated. Each mark of the pitch mark has a mark pattern different from at least each adjacent mark.
[0023]
The tip of the optical fiber is positioned with respect to the reference mark. For example, the tip of the optical fiber is located on an extension of one edge of the reference mark.
[0024]
Such an optical module is manufactured by the following manufacturing method.
[0025]
A step of preparing a substrate having an optical element mounting portion and a guide groove for guiding an optical fiber extending toward the optical element mounting portion on one surface; a step of fixing an optical element to the optical element mounting portion; A step of inserting and fixing an optical fiber in the guide groove so as to face the optical element, and a step of inspecting a distance between the optical element and the tip of the optical fiber to determine whether optical coupling is good or bad. A method of manufacturing a module, comprising:On one or both sidesAn optical fiber position measurement mark capable of measuring the amount of displacement of the fixed position of the tip of the optical fiberIs provided around the optical element mounting portion in the length direction of the guide groove and in the direction orthogonal to the guide groove.The amount of displacement of the fixed position of the optical element can be measured and the position measurement mark for the optical fiber andIn a certain positional relationshipProvide a position measurement mark for an optical element,The optical element mounting portion on one edge side or both edge sides of the guide groove;In a certain positional relationshipAnd the guide grooveWidth directionThe amount of displacementmeasurementA reference mark for,In fixing the optical element, the amount of positional deviation of the guide groove in the width direction with respect to the reference mark is determined.measurementAfter that, the optical element is fixed to the optical element mounting portion based on the measurement information, and after the optical element and the optical fiber are fixed, the position measurement mark for the optical fiber or the position measurement mark for the optical fiber and the optical element are fixed. The distance between the optical element and the tip of the optical fiber is measured using a position measurement mark, and the quality of the optical coupling between the optical element and the optical fiber is determined from the measured value.
[0026]
SaidOne guide groove edge of the guide groove and the one reference mark located outside the guide groove edge; the other guide groove edge of the guide groove and the other reference mark located outside the guide groove edge; ToTwo opticsCamera and monitor with measuring systemMeasured with an optical instrument having, The two obtained by the two optical measurement systemsthe imageOf the monitorProjected on the screen,Distance between the one guide groove edge and the one reference mark, and the other guide groove edge and the other reference markThe center position of the guide groove is determined from the measurement information, and the optical element is fixed to the substrate based on the center position.
[0027]
In fixing the optical fiber, the optical fiber is fixed using the fiducial mark as a reference at the time of fixing. For example, the optical fiber is fixed so that the tip of the optical fiber is located on an extension of one edge of the reference mark.
[0028]
The position measurement mark for the optical element and the position measurement mark for the optical fiber are described with a correlation. For example, they are simultaneously described by the same mark notation technology.
[0029]
The guide groove and the reference mark are simultaneously formed by the same etching process.
[0030]
The position measurement mark for the optical element and the position measurement mark for the optical fiber have a pitch mark configuration in which predetermined marks are arranged at a predetermined pitch so that the amount of positional deviation can be calculated. A distance between the optical element and the tip of the optical fiber is measured by measuring a pitch mark of the position measurement mark.
[0031]
According to the means (1), since (a) the optical fiber position measurement mark and the optical element position measurement mark are provided around the guide groove and the optical element mounting portion, respectively, It is possible to measure the amount of displacement between the fixed position of the optical element and the optical fiber.
[0032]
(B) Since the position measurement mark for the optical fiber and the position measurement mark for the optical element have a correlation, it is possible to measure the distance between the optical element and the tip of the optical fiber from the measurement of the fixed positional shift amount of the optical element and the optical fiber. it can. This makes it possible to determine the quality of the optical coupling state.
[0033]
(C) Since the position measuring mark for optical element and the position measuring mark for optical fiber have a pitch mark configuration, the positional deviation amount of the optical element and the optical fiber can be measured with high accuracy. Therefore, the distance between the optical element and the tip of the optical fiber can be measured with high accuracy, and the quality of optical coupling can be determined easily and with high accuracy.
[0034]
(D) Since each mark of the pitch mark has a different mark pattern from each of the adjacent marks, the calculation (measurement) of the positional deviation amount becomes easy and accurate.
[0035]
(E) Since the tip of the optical fiber is fixed so as to be located on an extension of one edge of the reference mark, there is a practical advantage that if the position is misaligned, it can be easily visually determined.
[0036]
(F) By not dividing a large area on the same screen and dividing the object to be measured into a large image on the same screen, measurement and measurement can be performed with high resolution. That is, since both edges of the guide groove including the fiducial mark are measured with an optical device having two optical paths and both images are projected on the same screen to measure the distance between each fiducial mark and each guide groove edge, The center position of the guide groove can be obtained with high accuracy. Therefore, the fixing accuracy of the optical element (semiconductor laser element) performed based on the center position is high, and the subsequent passive alignment is also high precision.
[0037]
(G) Although an optical device having a large field of view and high resolution is expensive, an image of each edge portion of the guide groove is divided and displayed on the same screen, so that an optical device having a small field of view can be used, and the optical module of the optical module can be used. Manufacturing costs can be reduced.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.
[0039]
(Embodiment 1)
1 to 9 are diagrams relating to an optical module according to a first embodiment of the present invention and a method of manufacturing the optical module.
[0040]
The optical module 1 of the first embodiment has a structure in which a plurality of leads 3 project in an in-line manner from both sides of a flat box-shaped package 2 as shown in FIGS. 2 and 3. A protruding optical fiber cable support 4 is provided at the center of one end of the package 2 to support the optical fiber cable 5.
[0041]
The package 2 is made of plastic and includes a case 6 and a cap 7 which is detachably attached to the upper surface of the case 6. The case 6 and the cap 7 are also provided with cable support portions 4a and 4b for constituting the optical fiber cable support portion 4.
[0042]
The upper surface of the case 6 is provided with a ridge fitting portion 8 such that the cap 7 fits slightly inward from the edge. The fitting portion 8 is open at one end of the cable support portion 4a, and has a structure that does not hinder the guide of the optical fiber cable 5. At the tip (inner end) of the optical fiber cable 5 guided by the cable support portion 4a, a fiber jacket serving as an exterior is peeled off to expose an optical fiber 11 composed of a core and a clad.
[0043]
Although not shown, the optical fiber cable support 4 and the portion of the optical fiber cable 5 protruding from the optical fiber cable support 4 are fixed by a cylindrical protective tube. This protective tube is formed of a heat-shrinkable tube, and after being attached to the optical fiber cable support portion 4, is heated and contracted to fix the optical fiber cable 5 to the optical fiber cable support portion 4.The optical fiber cable 5 may be fixed at the optical fiber cable support 4 using a bonding material or the like.
[0044]
A substrate 10 is fixed on the inner bottom of the fitting portion 8 of the case 6 via a joining material (not shown). The substrate 10 is a mounting substrate, for example, a silicon substrate. This substrate 10 is generally called a silicon platform 10.
[0045]
The silicon platform 10 has a rectangular shape as shown in FIGS. 1, 4 and 5, and has a tip portion of an optical fiber 11, a semiconductor laser element (LD) 12, and a light receiving element ( PD) 13 are sequentially fixed.
[0046]
The semiconductor laser element 12 and the light receiving element 13, which are optical elements, have alignment marks 16 and 17 provided on the optical element mounting portions 14 and 15, respectively, and alignment marks of the same pattern provided on the semiconductor laser element 12 and the light receiving element 13. And is fixed to the silicon platform 10.
[0047]
The optical fiber 11 is guided and inserted into a guide groove 20 having a V-shaped cross section, and is fixed to the silicon platform 10 by a fixing resin 21 (see FIG. 3). The optical fiber 11 extends from the optical fiber cable 5.
[0048]
The guide groove 20 is formed such that one end faces from one end side of the silicon platform 10 toward the vicinity of the optical element mounting portion 14 for fixing the semiconductor laser element 12.
[0049]
In the manufacturing of the optical module 1 of the first embodiment, the optical coupling between the semiconductor laser element 12 and the optical fiber 11 is performed by a passive alignment method.
[0050]
The optical fiber 11 is fixed to the silicon platform 10 by a fixing resin 21.
[0051]
Laser light emitted from the front end of the semiconductor laser element 12 is taken into the tip of the optical fiber 11. The laser light emitted from the rear end of the semiconductor laser element 12 is received by the light receiving element 13 and the light output is monitored.
[0052]
A bonding pad 27 is provided on an end surface of the silicon platform 10 on which the semiconductor laser element 12 and the light receiving element 13 are mounted. In these bonding pads 27, wiring extends from some of the bonding pads 27 and extends to the optical element mounting section 14 of the semiconductor laser element 12 or the optical element mounting section 15 of the light receiving element 13. It is electrically connected to the lower electrode of the light receiving element 13. Further, upper electrodes of the semiconductor laser element 12 and the light receiving element 13 and some bonding pads 27 are electrically connected by conductive wires 28.
[0053]
The tip portion of the optical fiber 11, the semiconductor laser element 12, and the light receiving element 13 are covered with a coating resin 29.
[0054]
The inner ends of the leads 3 projecting from both sides of the case 6 project inside the case 6, and the inner ends of the leads 3 and the bonding pads 27 are connected by conductive wires 9 (see FIG. 3). I have.
[0055]
On the other hand, this is one of the features of the present invention. As shown in FIG. 1, in the vicinity of the guide groove 20 and the optical element mounting portion 14, a positional shift amount of the tip fixing position of the optical fiber 11 is reduced. An optical fiber position measurement mark 30 that can be measured and an optical element position measurement mark 25 that can measure the displacement of the fixed position of the semiconductor laser element 12 and have a correlation with the optical fiber position measurement mark 30 are provided. .
[0056]
Further, reference marks 40 are provided on both sides of the guide groove 20 so as to correlate with the optical element mounting portion 14 and to measure the amount of positional deviation of the guide groove 20 in the width direction.
[0057]
Optical coupling between the semiconductor laser element 12 and the optical fiber 11 in the manufacture of the optical module 1 is performed by a passive alignment method. In this case, the tip of the optical fiber 11 is inserted into the guide groove 20 with respect to the semiconductor laser device 12 fixed to the silicon platform 10, and the optical fiber 11 is moved and adjusted in the axial direction (Y direction) of the optical fiber 11. The optical coupling between the semiconductor laser element 12 and the optical fiber 11 is performed by fixing the optical fiber 11.
[0058]
When the semiconductor laser element 12 is fixed with high accuracy of ± 2 μm, generally, the position of the tip of the optical fiber 11 is also often fixed at a preset position.
[0059]
Therefore, in the first embodiment, the optical fiber 11 is positioned based on the reference mark 40 from the semiconductor laser element 12 and the optical fiber 11 is fixed.
[0060]
In order to accurately and accurately determine the quality of optical coupling based on the measurement of the distance between the semiconductor laser element 12 and the tip of the optical fiber 11, the optical fiber position measurement mark 30 and the optical element position described above are used. A measurement mark 25 was provided.
[0061]
In general, there is a correlation between the position of the guide groove 20 and the position of the optical element mounting portion 14 for fixing the semiconductor laser element 12. For example, the guide groove 20 is formed so as to be positioned relatively to the alignment mark of the optical element mounting portion 14. The positioning and fixing of the optical fiber 11 is performed based on the idea that the positional relationship between the guide groove 20 and the optical element mounting portion 14 maintains sufficient positional accuracy in the passive alignment method.
[0062]
However, since the position of the guide groove 20 may be shifted in the groove width direction (X direction), it is not always preferable to use the alignment mark of the optical element mounting portion 14 to fix the semiconductor laser element 12 in a manufacturing lot. The present inventor has found out that there is no limitation, as a result of studying the failure generation mechanism.
[0063]
Therefore, reference marks 40 are provided on both sides of the guide groove 20, the amount of displacement of the guide groove 20 with respect to the reference mark 40 is measured, and the semiconductor laser element 12 is fixed based on the measurement information. By fixing the optical fiber 11, high-precision optical coupling between the semiconductor laser device and the optical fiber is performed.
[0064]
Hereinafter, the position measurement mark 25 for the optical element, the position measurement mark 30 for the optical fiber, and the reference mark 40 will be described, including the method of manufacturing the optical module 1.
[0065]
The optical element position measurement mark 25 and the optical fiber position measurement mark 30 provided on the surface (upper surface) of the silicon platform 10 are visible even after the semiconductor laser element 12 and the optical fiber 11 are fixed. It is a scale-type mark (pitch mark) from which the amount of displacement of the fixed position of the optical fiber 12 or the optical fiber 11 can be obtained by calculation.
[0066]
That is, the position measurement mark has a pitch mark configuration in which predetermined marks are arranged at predetermined pitches so that the amount of positional deviation can be calculated. In addition, each mark of the pitch mark has a mark pattern different from at least each adjacent mark. This is to prevent a detection error (read error), and in the case of the first embodiment, all marks are different marks as shown in FIG. In this example, each mark is composed of a combination of a point and a line of a predetermined length.
[0067]
The position measuring mark 25 for the optical element and the position measuring mark 30 for the optical fiber have a correlation with each other, and are written simultaneously by the same mark writing technique so that the position (distance) relationship becomes constant. The position measurement mark 25 for the optical element and the position measurement mark 30 for the optical fiber are formed by simultaneously forming an oxide film or a metallized film formed on the surface of the silicon platform 10 by photolithography or etching.
[0068]
In the silicon platform 10, in the first embodiment, the optical element position measurement mark 25 includes a Y-direction position shift detection mark 25y for detecting a position shift amount of the semiconductor laser element 12 in the Y direction, and a semiconductor laser element 12 in the X direction. And an X-direction position shift detection mark 25x for detecting the position shift amount.
[0069]
The Y-direction displacement detection marks 25y are arranged on both sides of the optical element mounting portion 14, and the X-direction displacement detection marks 25x are symmetrical with respect to the end face of the optical element mounting portion 14 on the guide groove 20 side and with respect to the optical axis 24. It is arranged as a simple pattern.
[0070]
The fixing accuracy of the semiconductor laser device is generally ± 2 μm. Therefore, in the Y-direction displacement detection mark 25y, each mark is formed by, for example, a single line having a width of 2 μm and a fixed length, a line of two lines, a line of three lines, and a line of three lines. One long line corresponding to three lines is sequentially formed. The gap between adjacent marks is also 2 μm.
[0071]
As a result, a pitch mark capable of detecting the amount of displacement with an accuracy of 2 μm is formed. Further, if the mark width and the gap can be visually divided into half, the amount of positional deviation can be detected with an accuracy of 1 μm.
[0072]
As a result, the amount of misalignment of the semiconductor laser element 12 in the Y direction can be read by a mark having a pitch mark configuration of the Y direction misalignment detection mark 25y.
[0073]
The widths and gaps of points and lines are not limited to the above numerical values.
[0074]
The X-direction displacement detection mark 25x is composed of a long mark overlapping the designed optical axis 24, and two marks symmetrically arranged with respect to this mark and sequentially shortened to form a pitch displacement mark. Is formed. The width of each mark is 2 μm, and the gap between the marks is 2 μm, as in the case of the Y-direction displacement detection mark 25y. This makes it possible to detect a positional deviation of 2 μm accuracy or 1 μm accuracy.
[0075]
Here, before describing the optical fiber position measurement mark provided around the guide groove 20, the reference mark 40 provided outside the edge of the guide groove 20 will be described.
[0076]
In the first embodiment, a total of four reference marks 40 are provided on both sides of the guide groove 20 symmetrically with respect to the optical axis 24. The reference mark 40 is formed by etching simultaneously with the guide groove 20. However, due to the size of the mask at the time of etching, that is, the difference in the opening size, the reference mark 40 is formed shallow and the guide groove 20 is formed deep. This can be easily obtained by changing the etching rate depending on the crystal plane orientation, for example, by setting the surface of the silicon platform 10 to the (100) plane.
[0077]
The depth of the guide groove 20 is formed with high precision by controlling the etching time with high precision.
[0078]
The guide groove 20 is formed so as to have a certain correlation (predetermined positional relationship) with at least the optical element mounting portion 14 (alignment mark or the like) for fixing the semiconductor laser element 12 in the manufacture thereof. Positional deviation occurs due to variations in the photolithography technology and etching technology when the guide groove 20 is formed by etching, the accuracy of a mask used in photolithography, and the like.
[0079]
As a result, when optical coupling between the semiconductor laser element and the optical fiber is performed by the passive alignment method, an optical axis alignment failure may occur.
[0080]
Therefore, in the first embodiment, in the manufacture of the optical module 1, the amount of displacement of the guide groove 20 is measured, and the fixed position of the semiconductor laser element is corrected based on the measurement information, so that the optical coupling by the passive alignment method can be performed. Things.
[0081]
Therefore, the reference marks 40 are formed on both sides of the guide groove 20 as described above, the amount of displacement of the guide groove 20 with respect to the reference mark 40 is measured, and then the semiconductor laser device is fixed.
[0082]
The groove width W of the guide groove 20 is, for example, 150 μm.The distance L from the edge is 20 μm, the groove width of the reference mark 40 is 20 μm, and the length of the reference mark 40 is 30 μm.FIG. 8 is an enlarged plan view of a part of the silicon platform 10 showing the guide groove 20 and the reference marks 40 provided on both sides of the guide groove 20, respectively.
[0083]
Generally, in order to view an image of 150 μm, an optical device having a visual field of 200 to 300 μm is required. When this is measured on one screen, the accuracy becomes 0.4 to 0.6 μm.
[0084]
When the field of view is set to about 50 μm, the image is projected on the screen in a large scale, so that the measurement accuracy can be increased to 0.1 μm.
[0085]
Therefore, in the first embodiment, the two sides of the guide groove 20 having a width of about 150 μm are divided into two optical measurement systems A constituted by prisms 41, 42a, 42b, 43a, 43b, and 44 as shown in FIG. Measurement is performed with a camera 49 having B and an optical device 45 having a monitor 46. The two divided images are displayed on the screen 47 of the monitor 46.
[0086]
On the screen 47, a right image 47a on the right surrounded by a two-dot chain line is an image obtained by the optical measurement system A, and a left image 47b on the left is an image obtained by the optical measurement system B. By displaying an image of the edge portion of the guide groove 20 including the reference mark 40 on the screen 47 in a close-up view, the distances a and b from the center of the reference mark 40 to the edge of the guide groove 20 are measured with an accuracy of 0.1 μm, for example. can do.
[0087]
Thus, the width of the guide groove 20 and the position of the center of the guide groove 20 can be obtained by calculation, and the amount of formation position deviation of the guide groove 20 can be obtained.
[0088]
Therefore, the semiconductor laser element 12 can be fixed to the optical element mounting portion of the silicon platform 10 by using a chip bonding apparatus 50 as shown in FIG. .
[0089]
In the chip bonding apparatus 50, a semiconductor laser element 12 is held by vacuum at a tip of a bonding arm 52 supported by an XY table 51 by a collet 53 made of transparent glass. Then, the XY table 51 is moved and adjusted in accordance with the displacement amount of the guide groove 20 to fix the semiconductor laser element 12 to the optical element mounting portion (not shown) of the silicon platform 10.
[0090]
FIG. 9A shows a fixed state of the optical fiber 11 in a state where the formation position does not shift in the guide groove 20, and FIG. 9B shows a state in which the formation position shift (ε) occurs in the guide groove 20. This shows a fixed state of the optical fiber 11. In the case of FIG. 9A, the optical axis alignment of the semiconductor laser element 12 and the optical fiber 11 is good, and in the case of FIG. 9B, the optical axis alignment of the semiconductor laser element 12 and the optical fiber 11 is poor.
[0091]
To observe the entire guide groove 20 as wide as 150 μm in one field of view, expensive optical equipment must be used. However, an optical equipment having two optical paths is inexpensive, and the manufacturing cost of the optical module 1 is reduced. Can be achieved.
[0092]
In this way, after measuring the amount of positional deviation of the guide groove 20, if the semiconductor laser element 12 is fixed based on the positional deviation, the light between the semiconductor laser element 12 and the optical fiber 11 is then passively aligned. Combinations can be made.
[0093]
When the optical fiber 11 is fixed to the guide groove 20 by the passive alignment method, an end face (one edge: fiber fixing reference) of the reference mark 40 (referred to as a chip-side reference mark 40) from the semiconductor laser element 12 toward the semiconductor laser element 12. Positioning is performed such that the tip of the optical fiber 11 is located at an extended portion of the optical fiber 11.
[0094]
The position measurement mark 30 for optical fiber has a pitch mark configuration as in the case of the position measurement mark 25 for optical element. Marks are displayed on both sides of the guide groove 20 at a predetermined pitch along the axial direction (Y direction) of the guide groove 20.
[0095]
A reference mark 31 is displayed on a portion of the reference mark 40 near the tip, which is located on an extension of the reference plane for fixing the fiber, and the displacement is zero (0). Then, a plus mark is displayed on the right side of the reference mark 31, and a minus mark is displayed on the left side. For example, the numerical value by the plus / minus mark is every 5 μm.
[0096]
Therefore, by confirming which mark the tip position of the optical fiber 11 corresponds to, it is possible to measure the positional deviation amount of the tip position of the optical fiber 11 accurately and with high accuracy.
[0097]
Although the reference mark 40 has a pitch mark configuration, these marks have mutually different patterns.
Each mark may be another pattern.
[0098]
The optical module 1 of the first embodiment is manufactured by the following method.
[0099]
After preparing the silicon platform 10 on which the guide groove 20 is formed as shown in FIG. 5, using the fiducial mark 40, the optical device having two optical paths is used to increase the positional deviation amount of the guide groove 20 as described above. Measure to accuracy.
[0100]
Thereafter, the semiconductor laser element 12 is fixed to the optical element mounting section 14 based on the measurement information.
[0101]
Next, the bonding pads 27 of the silicon platform 10 and the upper electrodes of the semiconductor laser device 12 and the light receiving device 13 are connected by wires 28. Further, the bonding pad 27 and the inner end of the lead 3 are connected by the wire 9.
[0102]
Next, the optical fiber 11 is positioned using the reference mark 40, and the optical fiber 11 is fixed to the guide groove 20 using the fixing resin 21.
[0103]
Next, the amount of misalignment between the semiconductor laser element 12 and the optical fiber 11 is measured using the optical element position measurement mark 25 and the optical fiber position measurement mark 30, and the distance between the semiconductor laser element 12 and the tip of the optical fiber 11 is measured. (D) is measured, and the quality of the optical coupling between the semiconductor laser element 12 and the optical fiber 11 is determined from the measured value.
[0104]
According to the first embodiment, the following effects can be obtained.
(1) The optical fiber position measurement mark 30 and the optical element position measurement mark 25 (X-direction position deviation detection mark 25x) are provided around the guide groove 20 and the optical element mounting portion 14 for fixing the semiconductor laser element 12, respectively. , Y-direction positional shift detection mark 25y), the amount of fixed positional shift between semiconductor laser element 12 and optical fiber 11 can be accurately measured.
[0105]
(2) Since the position measurement mark 30 for the optical fiber and the position measurement mark 25 for the optical element have a correlation, from the measurement of the fixed position shift amount of the semiconductor laser element 12 and the optical fiber 11, the measurement of the semiconductor laser element 12 and the optical fiber 11 is performed. The distance of the tip can be measured. This makes it possible to accurately and easily determine the quality of the optical coupling state.
[0106]
(3) Since the X-direction displacement detection mark 25x, the Y-direction displacement detection mark 25y, and the optical fiber position measurement mark 30 have a pitch mark configuration, the positions of the semiconductor laser element 12 and the optical fiber 11 can be accurately determined. The displacement amount can be measured. Therefore, the distance between the semiconductor laser element 12 and the tip of the optical fiber 11 can be measured with high accuracy, and the quality of optical coupling can be easily and accurately determined.
[0107]
(4) Since each mark of the pitch mark has a mark pattern different from that of each adjacent mark, the calculation (measurement) of the amount of positional deviation becomes easy and accurate.
[0108]
(5) Since the tip of the optical fiber 11 is fixed so as to be located on an extension of the fibre-fixed reference plane of the reference mark 40, there is a practical advantage that the position can be easily determined visually if the position is shifted.
[0109]
(6) Measurement objects can be measured and measured with high resolution by dividing the measurement target into small parts and projecting them on the same screen without projecting a large area on the same screen. In other words, since both edges of the guide groove including the reference mark are measured with an optical device having two optical paths, both images are projected on the same screen, and the distance between each reference mark and each guide groove edge is measured. The center position of the guide groove 20 can be obtained with high accuracy. Therefore, the accuracy of fixing the semiconductor laser device 12 based on the center position is high, and the subsequent passive alignment is also high accuracy.
[0110]
(7) Although an optical device having a large field of view and high resolution is expensive, an image of each edge portion of the guide groove 20 is divided and displayed on the same screen, so that an optical device having a small field of view can be used, and an optical module can be used. Can be reduced in manufacturing cost.
[0111]
(Embodiment 2)
FIG. 10 is a diagram showing an optical fiber position measurement mark according to another embodiment of the present invention. As shown in the figure, each mark of the optical fiber position measurement mark 30 in this embodiment has a binary notation configuration. That is, it is shown as a binary signal by filling a small square and blank.
[0112]
The second embodiment also has the same effects as the first embodiment.
[0113]
Although the invention made by the inventor has been specifically described based on the embodiment, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the invention. Nor.
[0114]
That is, the guide groove is formed with high precision in the optical element mounting portion, and when the precision is high, the reference mark is not necessarily required. In this case, the distance between the optical element and the tip of the optical fiber can be accurately measured by detecting the position measurement mark for the optical fiber and the position measurement mark for the optical element, and the quality of the product can be determined.
[0115]
As described in the above document, the fixing accuracy of the optical element (semiconductor laser element) is ± 2 μm. On the other hand, the fixed position accuracy of the optical fiber is significantly low at about ± 5 μm. Further, the change in the rate of taking in laser light in the optical fiber in the direction of the optical axis is more gradual than in the direction perpendicular to the optical axis.
[0116]
For this reason, when high accuracy is not required, only the position measurement mark for the optical fiber is provided without providing the position measurement mark for the optical element, and the distance between the optical element (semiconductor laser element) and the tip of the optical fiber is provided. May be measured to determine the quality of optical coupling.
[0117]
In the above description, the case where the invention made by the present inventor is mainly applied to an optical module manufacturing technique for a single optical fiber, which is a utilization field as a background, has been described, but is not limited thereto. The present invention can also be applied to a manufacturing technology of an optical module having a multi-core configuration in which a semiconductor laser element has an array structure, an optical fiber has a multi-fiber (fiber array), and guide grooves of a substrate are arrayed.
[0118]
INDUSTRIAL APPLICABILITY The present invention can be applied to at least a technology for manufacturing an optical module such as a light emitting optical module and a light receiving optical module.
[0119]
【The invention's effect】
The effects obtained by the typical inventions among the inventions disclosed in the present application will be briefly described as follows.
[0120]
(1) An optical fiber position measurement mark for measuring the amount of positional deviation of the fixed position of the tip of the optical fiber is provided around the guide groove for guiding the optical fiber, so that the position of the optical fiber can be easily and accurately determined. The displacement can be measured.
[0121]
(2) Since an optical element position measurement mark for measuring the amount of positional deviation of the fixed position of the optical element is provided around the optical element mounting portion for fixing the optical element (semiconductor laser element), it is simple and highly accurate. The amount of positional shift of the optical element can be measured.
[0122]
(3) Since the position measuring mark for the optical element and the position measuring mark for the optical fiber are formed with a correlation, the positional deviation amount of the optical element and the tip of the optical fiber as described in (1) and (2) above. , The distance between the optical element and the tip of the optical fiber can be accurately measured, and the quality of optical coupling between the optical element and the optical fiber can be accurately and easily determined.
[0123]
(4) Since a reference mark is provided on the side of the optical fiber as a reference for fixing the tip position of the optical fiber, positioning for fixing the optical fiber is facilitated.
[0124]
(5) The reference mark serves as a reference for measuring the amount of positional deviation of the guide groove, and the positional deviation of the guide groove is measured by measuring the distance between both sides of the guide groove and the reference mark. Therefore, measurement accuracy is improved.
[0125]
(6) Since the width of the guide groove and the continuation of the positional deviation can be measured by an optical device having two optical paths, an expensive optical device for projecting a wide area with high accuracy is not required, and the use of an inexpensive optical device. Thus, the manufacturing cost of the optical module can be reduced.
[Brief description of the drawings]
FIG. 1 is an enlarged plan view illustrating a main part of an optical module according to a first embodiment of the present invention.
FIG. 2 is a perspective view illustrating an appearance of the optical module according to the first embodiment.
FIG. 3 is an exploded perspective view of the optical module according to the first embodiment.
FIG. 4 is an enlarged sectional view showing a silicon platform and the like in the optical module according to the first embodiment.
FIG. 5 is an enlarged perspective view showing a silicon platform in the optical module according to the first embodiment.
FIG. 6 is a schematic view showing an outline of an optical device for measuring grooves and marks on a silicon platform in manufacturing the optical module of the first embodiment.
FIG. 7 is a schematic diagram showing an outline of a chip bonding apparatus for fixing a semiconductor laser device to a silicon platform in manufacturing the optical module of the first embodiment.
FIG. 8 is an enlarged plan view showing a part of the silicon platform provided with an optical fiber position measurement mark.
FIG. 9 is an enlarged sectional view showing a part of the silicon platform showing a good state and a bad state of the optical fiber fixed in the groove.
FIG. 10 is an enlarged plan view showing a part of a silicon platform in the optical module according to the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical module, 2 ... Package, 3 ... Lead, 4 ... Optical fiber cable support part, 4a, 4b ... Cable support part, 5 ... Optical fiber cable, 6 ... Case, 7 ... Cap, 8 ... Fitting part, 9 ... wires, 10 ... substrate (mounting substrate: silicon platform), 11 ... optical fiber, 12 ... semiconductor laser element (LD), 13 ... light receiving element (PD), 14, 15 ... optical element mounting part, 16, 17 ... alignment Mark, 20: guide groove, 21: fixed resin, 24: optical axis, 25: optical element position measurement mark, 25x: X-direction position shift detection mark, 25y: Y-direction position shift detection mark, 27: bonding pad, 28 ... wire, 29 ... coating resin, 30 ... position measurement mark for optical fiber, 31 ... reference mark, 40 ... reference mark, 41,42a, 42b, 43a, 3b, 44 ... prisms, 45 ... optical equipment, 46 ... monitor, 47 ... screen 49 ... camera, 50 ... chip bonding device, 51 ... XY table 52 ... bonding arm, 53 ... collet.

Claims (11)

A substrate having an optical element mounting portion and a guide groove for guiding an optical fiber extending toward the optical element mounting portion on one surface, an optical element fixed to the optical element mounting portion, and inserted along the guide groove; An optical fiber having a fixed end facing the optical element, the optical module having a fixed positional relationship with the optical element mounting portion on one edge side or both edge sides of the guide groove, and a width of the guide groove. An optical module comprising a reference mark for measuring an amount of displacement in a direction. A substrate having an optical element mounting portion and a guide groove for guiding an optical fiber extending toward the optical element mounting portion on one surface, an optical element fixed to the optical element mounting portion, and inserted along the guide groove; An optical module having an optical fiber fixed and having a tip facing the optical element,
An optical fiber position measurement mark provided on one edge side or both edge sides of the guide groove and capable of measuring a positional shift amount of a tip fixed position of the optical fiber ,
Provided around the optical element mounting portion, the guide groove in the longitudinal direction and the guide shift amount of the fixed position in the direction of the optical element that is perpendicular to the groove can measurement and constant the position measurement marks for optical fiber An optical element position measurement mark in a positional relationship ;
Provided on one edge or both edge side of the guide groove, the Rukoto which have a and the reference mark for measuring the positional deviation amount of width direction of the optical element mounting portion and enabled with the guide groove in a fixed positional relationship An optical module characterized by: Claim 1 or, characterized in that said light position measuring mark element and the position measurement marks for optical fiber is in a pitch mark configurations disposed a predetermined mark at a predetermined pitch so as to be able to calculate the position deviation amount The optical module according to claim 2 . 4. The optical module according to claim 3 , wherein each mark of the pitch mark configuration has a mark pattern different from at least each adjacent mark. Light module according to any one of claims 1 to 4, characterized in that the tip of the optical fiber is positioned with respect to the reference mark. A step of preparing a substrate having an optical element mounting portion and a guide groove for guiding an optical fiber extending toward the optical element mounting portion on one surface; a step of fixing an optical element to the optical element mounting portion; A step of inserting and fixing an optical fiber in the guide groove so as to face the optical element, and a step of inspecting a distance between the optical element and the tip of the optical fiber to determine whether optical coupling is good or bad. A method of manufacturing a module,
Provided on one edge side or both edge sides of the guide groove is an optical fiber position measurement mark capable of measuring the amount of deviation of the tip fixed position of the optical fiber ,
The amount of deviation of the fixed position of the optical element in the length direction of the guide groove and the direction perpendicular to the guide groove around the optical element mounting portion can be measured, and the positional relationship with the optical fiber position measurement mark is fixed. Providing a position measurement mark for an optical element ,
A reference mark is provided at one edge side or both edge sides of the guide groove, which has a fixed positional relationship with the optical element mounting portion and measures a positional shift amount in the width direction of the guide groove ,
In fixing the optical element, after measuring the amount of positional deviation of the guide groove in the width direction with respect to the reference mark, the optical element is fixed to the optical element mounting portion based on the measurement information,
After fixing the optical element and the optical fiber, the distance between the optical element and the tip of the optical fiber is measured using the optical fiber position measurement mark or the optical fiber position measurement mark and the optical element position measurement mark, A method of manufacturing an optical module, comprising determining whether optical coupling between an optical element and an optical fiber is good or bad based on the measured value. One guide groove edge of the guide groove, the one reference mark located outside the guide groove edge, the other guide groove edge of the guide groove, and the other reference mark located outside the guide groove edge the preparative, measured with an optical device having a camera and a monitor with two optical measuring system, Projected two images obtained by the two optical measuring system on the screen of the monitor, the one guide groove edge and The distance between one reference mark and the distance between the other guide groove edge and the other reference mark are measured, the center position of the guide groove is obtained from the measurement information, and the optical element is determined based on the center position. The method for manufacturing an optical module according to claim 6 , wherein the optical module is fixed to the substrate. The method of manufacturing an optical module according to claim 6 or claim 7, characterized in that the fixing of the optical fiber as a reference at the time of fixing the reference mark in the fixation of the optical fiber. Manufacturing the optical module according to any one of claims 6 to 8 wherein the optical element for position measurement mark and the position measurement mark for optical fiber is characterized in that simultaneously formed by photolithography and etching techniques Method. It said guide grooves and said reference mark optical module manufacturing method according to any one of claims 6 to 9, characterized in that simultaneously formed by the same etching process. The position measurement mark for the optical element and the position measurement mark for the optical fiber have a pitch mark configuration in which predetermined marks are arranged at a predetermined pitch so that the amount of positional deviation can be calculated. the method of manufacturing an optical module according to any one of claims 6 to 10 to measure the pitch mark position measurement mark and measuring the distance of the optical fiber tip and the optical element.

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