JP2009200064A - Method of manufacturing light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a light-emitting device capable of particularly, properly and easily positioning the light-emitting surfaces of a plurality of light-emitting elements at the same height. <P>SOLUTION: Surface light-emitting lasers 12, 13 are so secured by means of a tool 30 that the light-emitting surfaces 12b, 13b of the surface light-emitting elements 12, 1 are in contact with a facing flat surface 30 of the tool 30. With the light-emitting surfaces 12b, 13b positioned at the same height, the jig 30 is moved near a base 50, and the surface light-emitting lasers 12, 13 are joined to the base 50 with molten solder 53. The solder 53 is hardened to secure the surface light-emitting lasers 12, 13 onto the base 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting device used in, for example, a hologram reproducing device.

  As described in the following patent document, in reproduction of hologram data, when reproduction reference light is incident on a recording medium on which hologram data is recorded, the reproduction reference light is interfered with the data by Bragg conditional expression. The light is diffracted by the fringes and emitted. Then, the content of the hologram data contained in the reproduction light is read out by an image pickup device such as a CCD or CMOS sensor.

  By the way, as described in the following patent document, for example, a surface emitting laser array in which a plurality of surface emitting lasers (VCSEL) are arranged is used for the light emitting device that emits the reproduction reference light.

  The advantage of using a plurality of surface emitting lasers in this way is that the wavelength band of the reproduction reference light can be widened easily and inexpensively. That is, a wide wavelength band can be obtained by combining a plurality of surface emitting lasers having different wavelength bands of the reproduction reference light. Such a surface emitting laser array having a wide wavelength band can cover the entire wavelength band when multiple hologram data are recorded in a wide wavelength band by wavelength multiplexing. is there. Therefore, each hologram data can be reproduced appropriately.

Further, when the hologram data recorded at the wavelength α cannot be reproduced at the wavelength α due to, for example, anisotropic thermal expansion of the recording medium, the hologram data must be reproduced at a wavelength β different from the wavelength α. If the surface emitting laser is, it is possible to appropriately reproduce the hologram data by switching to the surface emitting laser having the wavelength.
JP 2005-331864 A JP 2006-58726 A JP 2003-233293 A

  However, in the process of manufacturing the surface emitting laser, the surface emitting laser has a thickness variation.

  When the thickness of the surface emitting laser varies, the following problems occur. The problem will be described below.

  As shown in FIG. 15, for example, two surface emitting lasers 2 and 3 are installed on the substrate 1. A surface emitting laser array 6 is configured by including the substrate 1 and the surface emitting lasers 2 and 3.

  As shown in FIG. 15, a lens 4 is provided between the surface emitting laser array 6 and the recording medium 5. With this lens 4, the reproduction reference beams 2 a and 3 a irradiated from the surface emitting lasers 2 and 3 are adjusted to parallel beams.

  By the way, as shown in FIG. 15, since the surface emitting lasers 2 and 3 have different thicknesses, the light emitting surfaces (surfaces of the light emitting portions) 2b and 3b of the surface emitting lasers 2 and 3 are high when viewed from the substrate 1. It is different. Therefore, the distance H1 between the light emitting surface 2b of the surface emitting laser 2 and the principal point 4a of the lens 4 and the distance H2 between the light emitting surface 3b of the surface emitting laser 3 and the principal point 4a of the lens 4 are different. End up.

  Therefore, for example, even if the reproduction reference light 3a is adjusted to parallel light by controlling the distance H2 between the light emitting surface 3b of the surface emitting laser 3 and the principal point 4a of the lens 4, the other reproduction reference light is used. 2a, since the distance H1 between the light emitting surface 2b and the principal point 4a is shorter than the distance H2, it becomes diffused light as shown in FIG. 15, or when the distance H1 becomes longer than the distance H2, the focused light. End up. When the light becomes diffuse light or focused light, the entire hologram data 7 is not irradiated with parallel light, and the incident angle with respect to each interference fringe of the hologram is different, resulting in a problem that the hologram data 7 cannot be reproduced.

  In addition, even when the thickness of the surface emitting laser is the same, the surface emitting laser is caused by a variation in the thickness of the adhesive layer interposed between the surface emitting laser and the substrate for fixing the surface emitting laser on the substrate. The height position of the light emitting surface may vary.

  Therefore, the present invention is for solving the above-described conventional problems, and in particular, manufacturing a light-emitting device capable of appropriately and easily suppressing variations in height of each light-emitting surface of a plurality of light-emitting elements than in the past. It aims to provide a method.

The present invention relates to a method for manufacturing a light emitting device in which a plurality of light emitting elements are provided on a substrate.
With the light emitting surfaces of the plurality of light emitting elements being adjusted to the same height on the substrate, the light emitting elements are adhered to the substrate via an adhesive,
Thereafter, the adhesive is cured to fix the light emitting element on the substrate.

  Thereby, even if the thickness of the plurality of light emitting elements varies (at least one light emitting element is formed with a different film thickness from other light emitting elements), each light emitting surface of the light emitting element can be appropriately and easily obtained. Can be adjusted to the same height. In addition, since the bonding process and the fixing process are performed at a time with the light emitting surfaces of the respective light emitting elements being set to the same height, the manufacturing process can be simplified without separately bonding and fixing the respective light emitting elements. And when the light-emitting device manufactured with the manufacturing method of this invention is used for a hologram reproduction apparatus, the hologram reproduction apparatus which has a highly accurate reproduction | regeneration function can be manufactured.

  In the present invention, a plurality of the light emitting elements are attached to a jig, the respective light emitting surfaces are matched to the same height, and the light emitting elements are brought into close contact with a substrate via an adhesive while maintaining the same height, It is preferable to remove the jig after the adhesive is cured. Since it is possible to perform the height alignment of each light emitting surface, and the subsequent adhesion step to the adhesive and the fixing step using the jig, the light emitting element is positioned on the substrate with high accuracy. It can be fixed together, and the manufacturing process can be simplified.

Moreover, in this invention, it is preferable to have the following processes.
(A) The light emitting element is prepared in a state in which the light emitting surface is opposed to the light emitting surface, the jig having the same plane formed thereon, and the light emitting surfaces of the plurality of light emitting elements in contact with the same plane. Fixing to the jig;
(B) The jig is opposed to the substrate, and at this time, the light emitting surfaces of the plurality of light emitting elements are matched to the same height, and the gap between the substrate and the light emitting elements is maintained while maintaining the same height. Adhering via the adhesive;
(C) curing the adhesive and fixing the light emitting element on the substrate;
(D) A step of releasing the fixed state between the light emitting element and the jig and removing the jig.

  By using the jig described above, it is possible to manufacture a light emitting device in which the light emitting surfaces of the plurality of light emitting elements are adjusted to the same height more easily and with higher accuracy.

The present invention also relates to a method for manufacturing a light emitting device in which a plurality of light emitting elements are provided on a substrate.
A jig is prepared in which opposing surfaces facing the respective light emitting surfaces of the plurality of light emitting elements are formed on the same plane, and each light emitting element is brought into contact with the same plane of the jig from the light emitting surface side. In a state of being fixed to, the light emitting element is closely attached to the substrate via an adhesive,
Thereafter, the adhesive is cured, the light emitting element is fixed on the substrate, the fixing state between the light emitting element and the jig is released, and the jig is removed. It is.

  Thereby, the dispersion | variation in the height of each light emission surface of the said several light emitting element can be suppressed conventionally and easily.

  In the present invention, electrodes are provided on the surface opposite to the light emitting surface of the light emitting element and the surface of the substrate, respectively, and a groove is formed on at least one of the light emitting element side electrode and the substrate side electrode. Preferably, the adhesive is provided on the electrode formed and excluding the groove. The groove can function as an escape groove for, for example, releasing excess adhesive when the light emitting element is brought into close contact with the substrate.

  In the present invention, electrodes are provided on the surface opposite to the light emitting surface of the light emitting element and the surface of the substrate, respectively, and a conductive adhesive is used as the adhesive, and the light emitting element side It is preferable that the electrode and the substrate-side electrode are electrically connected via the conductive adhesive.

  At this time, it is preferable to use solder for the conductive adhesive. Thereby, the substrate side electrode and the light emitting element side electrode can be easily connected to each other. In addition, when solder is used, the substrate-side electrode and the light-emitting element-side electrode can be firmly bonded by metal bonding. For example, when the jig is removed, the thickness of the adhesive layer varies, Thermal shrinkage and thermal expansion due to changes and the like can be suppressed as much as possible, and fluctuations in the height of each light emitting surface of the light emitting element can be appropriately suppressed after manufacturing.

  Moreover, in this invention, it is preferable to use the electrically conductive paste containing an organic component for the said electrically conductive adhesive, and to remove the said organic component by heat processing in the case of hardening of the said electrically conductive adhesive. When organic components are contained even after curing, for example, when the jig is removed, the film thickness of the adhesive layer varies, and after production, thermal shrinkage and thermal expansion are likely to occur due to environmental temperature changes, etc. By removing the organic component, it is possible to appropriately suppress the fluctuation of the height of each light emitting surface of the light emitting element after manufacturing.

  In the present invention, the adhesive is preferably interspersed between each light emitting element and the substrate. When the entire surface between the substrate and the light emitting element is brought into close contact with the adhesive, pores sealed at the interface between the substrate and the adhesive, the interface between the light emitting element and the adhesive, and the like are likely to be generated. In such a case, the air existing in the holes due to a change in environmental temperature or the like causes thermal contraction or thermal expansion, so that the adhesion between the substrate and the light emitting element tends to be lowered. Further, when the light emitting element and the substrate are brought into close contact with each other, there is a possibility that excess adhesive spreads around the light emitting element. Therefore, the said problem can be solved by interspersing the said adhesive agent.

  According to the present invention, even if the thickness of the plurality of light emitting elements varies, it is possible to appropriately and easily match the light emitting surfaces of the light emitting elements to the same height. Therefore, when the light emitting device manufactured by the manufacturing method of the present invention is used in a hologram reproducing device, a hologram reproducing device having a highly accurate reproducing function can be manufactured.

  FIG. 1 is a conceptual diagram of reproducing hologram data from a recording medium by a hologram reproducing apparatus. 2 to 5 are process diagrams (both are partial cross-sectional views cut from the thickness direction) showing a method for manufacturing the light emitting device (surface emitting laser array) in the present embodiment. FIG. 6 is a partial plan view of the surface emitting laser and the jig shown in FIG. 7 and 8 are process diagrams showing a preferred example of the method for manufacturing a light-emitting device according to the present embodiment (FIG. 7 is a process diagram replacing the process of FIG. 3 and is an enlarged view of FIG. 3. FIG. 8 is an enlarged cross-sectional view, and FIG. 8 is a process diagram in place of the process of FIG. 9 and 10 are process diagrams showing a preferred example of the method for manufacturing the light emitting device according to the present embodiment (FIG. 9 is cut in the thickness direction along the line AA shown in FIG. 11 and viewed from the arrow direction. FIG. 10 is a partial enlarged cross-sectional view of the substrate and the adhesive (solder), and FIG. 10 shows the substrate, the surface-emitting laser, and the adhesive (solder) part in a state where the surface-emitting laser and the substrate are joined after the step of FIG. FIG. FIG. 11 is a partially enlarged plan view of the substrate and the adhesive (solder) shown in FIG. 9 viewed from directly above. FIG. 12 is a partially enlarged plan view of the substrate and the adhesive (solder) showing the shape of the substrate different from that in FIG. 13 is a partial cross-sectional view of the substrate in which a surface emitting laser is bonded to the substrate shown in FIG. 12, the adhesive (solder), and the surface emitting laser are cut in the thickness direction (the cutting position is shown in FIG. 13). 12 before one step is the BB line shown in Fig. 12. The partial cross-sectional view of Fig. 13 is cut in the thickness direction along the BB line and viewed from the arrow direction. Yes). FIG. 14 is a conceptual diagram for explaining the irradiation state of the reproduction reference light irradiated from each surface emitting laser by incorporating the surface emitting laser array manufactured by the manufacturing method according to the present embodiment into the hologram reproducing apparatus.

  A hologram reproducing apparatus 10 shown in FIG. 1 includes a surface emitting laser array 14 in which a plurality of surface emitting lasers (VCSEL) (light emitting elements) 12 and 13 are formed on the same substrate 50, a lens array 17, a CCD, and a CMOS. The image sensor 18 which consists of sensors etc., the pinhole filter 19, and the installation part (not shown) for installing the recording medium 20 are comprised.

  As shown in FIG. 1, hologram data 21 is recorded on a recording medium 20 by a hologram recording device (not shown). The hologram data 21 appears as interference fringes. Although only one hologram data 21 is shown in FIG. 1, a large number of hologram data 21 are actually recorded by wavelength multiplexing or angle multiplexing.

  Now, the reproduction reference beam 22 is irradiated toward the recording medium 20 from the surface emitting laser 12 of the hologram reproducing apparatus shown in FIG. The light diameter of the reproduction reference light 22 is expanded by the microlens 15 and further collimated by the collimating lens 16.

  The reproduction reference beam 22 is applied to the recording medium 20 at an irradiation angle θ1. When the reproduction reference beam 22 is applied to the hologram data 21, the light is diffracted by the interference fringes satisfying the Bragg conditional expression, and the reproduction beam (diffracted beam) 23 is directed from the recording medium 20 toward the image sensor 18. Released. At this time, the reproduction light 23 reaches the image sensor 8 through a pinhole 19 a provided in the pinhole filter 19. In the image sensor 8, the contents of the hologram data 21 are reproduced. The reason why the pinhole filter 19 is provided is that, when the reproduction reference light 22 is irradiated onto the recording medium 20, when the reproduction light of a plurality of hologram data is emitted from the recording medium 20, one of the reproduction lights 23 is provided in order for the image sensor 18 to receive light appropriately. By providing the pinhole filter 19, it is possible to appropriately reproduce the plurality of hologram data 21.

  In the present embodiment, the light emitting surfaces of the plurality of surface emitting lasers 12 and 13 installed on the substrate 50 are formed at the same height as viewed from the reference surface. Hereinafter, a method for manufacturing the surface emitting laser array 14 in the present embodiment will be described.

  As shown in FIG. 2, light emitting portions 12a and 13a are formed on the surface sides of the surface emitting lasers 12 and 13, and the surfaces of the surface emitting lasers 12 and 13 are light emitting surfaces 12b and 13b. Surface electrodes 31 and 32 appear on the light emitting surfaces 12b and 13b.

  Here, in FIG. 2, the light emitting surfaces 12 b and 13 b are shown as surfaces of the entire surface emitting lasers 12 and 13, but the “light emitting surface” is a surface irradiated with light from the surface emitting lasers 12 and 3. Strictly speaking, it refers to the exposed surfaces of the light emitting portions 12a and 13a or the surfaces facing the light emitting portions 12a and 3a.

  In the present embodiment, it is preferable that the surface processing (light emitting surface) of the light emitting units 12 and 13 is planarized so as to be a flattened surface. Further, it is more preferable that the surface of the light emitting units 12 and 13 and at least a part of the surrounding surface thereof are processed by plane processing. Most preferably. In FIG. 2, the surfaces of the surface electrodes 31 and 32 are formed in the same plane as the light emitting surfaces 12b and 3b. For example, the surface electrodes 31 and 32 shown in FIG. The surface of the surface electrodes 31 and 32 may protrude from the surface of the light emitting units 12 and 13.

  In the following description, unless otherwise specified, as shown in FIG. 2, the surfaces of the surface electrodes 31 and 32 are formed in the same plane as the light emitting surfaces 12b and 3b, and the entire surfaces of the surface emitting lasers 12 and 13 are formed. This will be described as “light emitting surfaces 12b and 13b”.

  Further, as shown in FIG. 2, back surface electrodes (light emitting element side electrodes) 33 and 34 appear on the surfaces of the surface emitting lasers 12 and 13 opposite to the light emitting surfaces 12b and 13b, that is, on the back surfaces 12c and 13c. .

  As shown in FIG. 2, the thickness dimension of the surface emitting laser 12 is H3, the thickness dimension of the surface emitting laser 13 is H4, and the thickness dimensions H3 and H4 are different. Here, the thickness dimension refers to a thickness dimension from the light emitting surfaces 12b and 13b to the back surfaces 12c and 13c (in this case, the thickness of the back electrodes 33 and 34 may be added). In the present embodiment, it is not essential that the surface emitting lasers 12 and 13 have different thickness dimensions H3 and H4. That is, the thickness dimensions H3 and H4 may be the same. However, when the thickness dimensions H3 and H4 are different, it is preferable to use the method of manufacturing the surface emitting laser array 14 in the present embodiment because the effects of the present invention are appropriately exhibited.

  As shown in FIG. 2, a jig 30 having a surface 30 a facing the light emitting surfaces 12 b and 13 b of the surface emitting lasers 12 and 13 formed on the same plane C is prepared. In this specification, the “jig” refers to a tool for carrying the surface emitting lasers 12 and 13 to a predetermined position on the substrate 50 with the surface emitting lasers 12 and 13 attached. The material of the jig 30 is not particularly limited, but is transparent or semi-transparent as will be described later, and the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13 are transparent from the surface 30c side of the jig 30. It is preferable to see. As shown in FIG. 6, the planar area of the jig 30 is larger than the total area of the planar areas of the surface emitting lasers 12 and 13. The planar shape of the jig 30 is not particularly limited. In FIG. 6, the planar shape of the jig 30 is rectangular.

  A suction hole 30b is formed in the jig 30 at a position facing a part of the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13. A suction mechanism (not shown) is provided separately or integrally with the jig 30, and the suction hole 30 b is in a state where the light emitting surfaces 12 b and 13 b are in contact with the facing surface 30 a of the jig 30. Then, the air is pulled upward from and the surface emitting lasers 12 and 13 are attracted and fixed to the facing surface 30a of the jig 30 by suction. However, another fixing method may be used.

  Here, the “contact” includes not only the case where the entire light emitting surfaces 12b and 13b and the entire opposing surface 30a are in complete contact, but also the case where there is a slight gap. That is, it is only necessary that at least a part is in contact and the surface emitting lasers 12 and 13 are fixed by the jig 30. For example, as described above, when the surface electrodes 31 and 32 are formed to protrude on the light emitting surfaces 12b and 13b, a step is generated between the light emitting surfaces 12b and 13b and the surfaces of the surface electrodes 31 and 32. Therefore, strictly speaking, the entire light emitting surfaces 12b and 13 and the entire facing surface 30a are not completely in contact with each other, and a gap is formed.

  As described above, the facing surface 30a of the jig 30 is formed on the same plane C, and in the step of FIG. 2, the light emitting surfaces 12b and 13b of the plurality of surface emitting lasers 12 and 13 are brought into contact with the facing surface 30a. The surface emitting lasers 12 and 13 are fixed by the jig 30 in the contact state.

  The positioning of the surface emitting lasers 12 and 13 with respect to the jig 30 is such that the jig 30 is transparent or translucent, and the surface emitting lasers 12 and 13 are placed from the surface 30c of the jig 30 as shown in FIG. When the light emitting surfaces 12b and 13b are seen through, the positioning mark portion 40 on the surface 30c or the opposing surface 30a of the jig 30 and on the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13, 41 can be provided and the mark portions 40 and 41 can be aligned. The positioning mark portion 40 shown in FIG. 6 is formed on the jig 30 side, and the positioning mark portion 41 shown in FIG. 6 is provided on the light emitting surfaces 12 b and 3 b of the surface emitting lasers 12 and 13. It is what was done. For example, the mark portions 40 and 41 are straight on a virtual line D parallel to the Y direction (length direction) in the drawing and on a virtual line E parallel to the X direction (direction perpendicular to the Y direction in the drawing, width direction). The surface emitting lasers 12 and 13 are positioned with respect to the jig 30 so as to line up with each other. Thereby, the surface emitting lasers 12 and 13 can be accurately positioned in both the X direction and the Y direction shown in the drawing.

  Next, in the step shown in FIG. 3, the substrate 50 is placed on the base 54. Substrate side electrodes 51 and 52 are formed on the surface of the substrate 50 at positions facing the surface emitting lasers 12 and 13. In the process of FIG. 3, a conductive adhesive 53 is applied on the substrate-side electrodes 51 and 52.

  In this embodiment, solder is used for the conductive adhesive 53. Below, the code | symbol 53 is demonstrated as solder.

  For the solder 53, an alloy mainly containing tin (Sn) is preferably used. In this case, Sn accounts for 50% by mass or more, more preferably 90% by mass or more, based on the total solder particles. As a metal forming an alloy with Sn, gold (Au), silver (Ag), copper (Cu), nickel (Ni), bismuth (depending on the purpose of the melting point of the solder or the electrical conductivity) One or more of Bi), antimony (Sb), zinc (Zn), and indium (In) can be selected. For example, since gold, silver, and copper have high electrical conductivity, Sn—Au, Sn—Ag, Sn—Cu, Sn—Ag—Cu alloys, etc., form solder with high electrical conductivity, but have a melting point. It is as high as 200 to 300 ° C. Further, the solder made of the Sn—Bi alloy has a low melting point of 60 to 200 ° C. and is excellent in workability, and hardly causes thermal damage to the substrate and the surface emitting laser. In particular, Sn—Bi has a melting point of about 140 ° C. and is optimal as a low melting point solder.

In the present embodiment, Sn—Au solder is preferably used for the solder 53.
The thickness of the solder 53 is about 10 to 30 μm. The solder 53 is thicker than the conventional one. In this embodiment, if the thickness of the surface emitting lasers 12 and 13 varies, there will be a difference in the distance between the surface emitting lasers 12 and 13 and the substrate 50 via the solder 53, as will be described with reference to FIG. Arise. In order to fix all the surface emitting lasers 12 and the substrate 50 appropriately with the solder 53 even if the gaps are different in this way, the film thickness of the solder 53 is set to be thicker than before.

  As shown in FIG. 3, the surface emitting lasers 12 and 13 fixed to the jig 30 are opposed to the substrate 50. At this time, the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13 are opposed to each other. Are adjusted so that they are at the same height position. The reference plane at the height position of the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13 can be arbitrarily set. For example, the reference surface is the front surface (back surface of the substrate 50) 54a of the base 54 shown in FIG. In this case, the jig 30 is adjusted so that the opposing surface 30a (same plane C) of the jig 30 and the surface 54a are parallel to each other. Thereby, the height of each light emitting surface 12b, 13b can be made the same height from the surface 54a. Alternatively, the surface of the substrate 50 may be the reference surface having the height.

  The solder 53 is heated and melted by laser irradiation or the like. And while maintaining the above-mentioned light emitting surfaces 12b and 13b at the same height, that is, when the height reference surface is the surface 54a of the base 54, the opposing surface 30a of the jig 30 and the surface 54a. The jig 30 is gradually brought closer to the substrate 50 while maintaining a parallel state.

  Then, as shown in FIG. 4, the surface emitting lasers 12 and 13 are simultaneously pressed against the solder 53, and the surface emitting lasers 12 and 13 and the substrate 50 are simultaneously brought into close contact with each other through the molten solder 53. .

  As described with reference to FIG. 2, the surface emitting laser 12 is thinner than the surface emitting laser 13. Therefore, in the state where the surface emitting lasers 12 and 13 and the substrate 50 are in close contact with each other through the solder 53 as shown in FIG. 4, the interval H6 between the surface emitting laser 12 and the substrate 50 is the same as that of the surface emitting laser 13. It becomes larger than the interval H5 between the substrates 50. As described above, in the present embodiment, since the thickness of the solder 53 is larger than that of the conventional one, the solder 53 can be appropriately interposed in the wide space H6.

  As shown in FIG. 4, the surface emitting lasers 12 and 13 are fixed by the jig 30, and the heights of the light emitting surfaces 12b and 13b are set to the same height, so that the surface emitting lasers 12 and 13 and the substrate are formed. The solder 53 is hardened while maintaining a state in which 50 spaces are in close contact with each other via the solder 53. Curing of the solder 53 is gradually promoted as the temperature decreases. In order to accelerate the hardening of the solder 53, the solder 53 may be forcibly cooled by a cooling mechanism (not shown).

  As a result, the surface emitting lasers 12 and 13 can be simultaneously fixed on the substrate 50 via the solder 53. Then, suction from the suction hole 30b of the jig 30 is stopped, the fixed state between the jig 30 and the surface emitting lasers 12 and 13 is released, and the jig 30 is removed.

  As shown in FIG. 5, the surface electrodes 31 and 32 of the surface emitting lasers 12 and 13 and the substrate side electrodes 55 and 56 formed on the surface of the substrate 50 are electrically connected by, for example, wires 57 (wires). bonding).

  As shown in FIG. 5, the surface-emitting lasers 12 and 13 and the substrate 50 are fixed with solder 53, whereby the back electrodes 33 and 34 of the surface-emitting lasers 12 and 13 and the substrate 50 side of the substrate 50 are fixed. The electrodes 51 and 52 can be conductively connected.

  According to the manufacturing method of this embodiment described above, the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13 can be formed at the same height when viewed from the reference surface. Here, the “same height” includes an error of about ± 2 μm.

  In this embodiment, by using the jig 30 having the opposing surface 30a formed on the same plane C, it is possible to easily and appropriately attach the surface emitting lasers 12 and 13 onto the substrate 50. That is, there is no need to separately adjust the height positions of the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13, and the same plane C is parallel to the reference surface (for example, the surface 54a shown in FIG. 3). Since the surface emitting lasers 12 and 13 may be brought into close contact with the substrate 50 via the solder 53 while maintaining the above, the height alignment of the light emitting surfaces 12b and 13b can be performed at one time. Since the surface-emitting lasers 12 and 13 can be simultaneously adhered to the substrate 50 and the surface-emitting lasers 12 and 13 can be simultaneously fixed on the substrate 50 by curing the solder 53 at the same time. The process can be simplified.

  2 to 5, solder 53 is used. The solder 53 is made of only metal and does not contain an organic component. The surface-emitting lasers 12 and 13 and the substrate 50 (between the solder 53 and the surface-emitting lasers 12 and 13, the solder 53 and the substrate 50, and the inside of the solder 53) are firmly bonded by metal bonding. When the organic component is included, when the jig 30 is removed and the pressing state of the jig 30 toward the substrate 50 is released, the height of the adhesive layer slightly varies, and the light emitting surfaces 12b and 13b The height of can vary. In addition, when an organic component is included, the height of each light emitting surface 12b, 13b varies due to a change in environmental temperature due to a difference in thermal expansion coefficient from the metal, or the adhesive layer and the surface emitting lasers 12, 13 or the adhesive layer and the substrate. Adhesion between 50 may be lowered. Therefore, it is better not to contain organic components.

  The organic component should not be included after the step of FIG. 5, that is, after the step of curing the adhesive.

  Therefore, a conductive paste containing an organic component is used as the conductive adhesive interposed between the substrate 50 and the surface emitting lasers 12 and 13, and the organic component is removed by heat treatment when the conductive adhesive is cured. It may be removed. As the conductive paste, for example, a resin having metal resinate or metal particles and an organic vehicle (an organic solvent and a resin binder) can be used. The organic component is thermally decomposed and evaporated during the heat treatment. As a result, the organic component does not remain in the adhesive layer finally, and it is possible to form the adhesive layer with only the metal. Even if the organic component is contained in the adhesive layer by several mass%, the conductive adhesive is, for example, compared with the case where an anisotropic conductive paste (ACP) or an anisotropic conductive film (ACF) is used. The film thickness variation of the adhesive layer when the jig 30 is removed can be reduced. In addition, when a metal resinate or the like is used as described above, since organic components are removed, the film thickness when the conductive adhesive is applied on the substrate 50 and the adhesion after the heat treatment in the step of FIG. The thickness of the layer varies greatly. Therefore, it is necessary to adjust the film thickness of the conductive adhesive in consideration of the film thickness reduction amount and the intervals H5 and H6 shown in FIG.

  2 to 5 are methods for manufacturing one surface emitting laser array 14. However, for example, in order to manufacture a plurality of surface emitting laser arrays 14 at once, a large number of substrates are formed on a large substrate. A surface emitting laser is fixed in the steps shown in FIGS. 2 to 5, and then the substrate is cut into each surface emitting laser array 14 to form a plurality of the surface emitting laser arrays 14 at one time. Is possible.

  In the process of FIG. 2, the solder 53 is applied to the entire surface of the substrate-side electrodes 51 and 52 on the substrate 50. However, when the solder 53 is applied to the entire surface of the substrate-side electrodes 51 and 52, as shown in FIG. 4, in particular, the solder 53 interposed between the surface-emitting laser 13 and the substrate 50 on the more pressed side is The extra amount is large, and extra solder 53 may flow out from the periphery of the surface emitting laser 13 and adhere to an unexpected location. Further, when the substrate 50 and the surface emitting lasers 12 and 13 are brought into close contact with each other via the solder 53, the solder 53 and the substrate 50, or between the solder 53 and the surface emitting lasers 12 and 13. Air holes sealed in between are easily formed. When the holes are formed, the air existing in the holes is thermally expanded or compressed due to a change in environmental temperature or the like, and between the solder 53 and the surface emitting lasers 12 and 13, and between the solder 53 and the substrate 50. There is a risk of reducing the adhesion between them.

  Therefore, as shown in FIG. 7, it is preferable that a plurality of spherical solders 60 are scattered on the substrate-side electrodes 51 and 52 on the substrate 50. The shape of the solder 60 is not limited to a spherical shape. The shape is not limited as long as the solder 60 is scattered.

  After the solder 60 is scattered on the substrate side electrodes 51 and 52 as shown in FIG. 7, the solder 60 is melted.

Then, as shown in FIG. 8, the surface emitting lasers 12 and 13 and the substrate 50 are brought into close contact with each other through the solder 60. At this time, the solder 60 interposed between the thicker surface emitting laser 13 and the substrate 50 is crushed more than the solder 60 interposed between the surface emitting laser 12 and the substrate 50.
Then, the solder 60 is cured in the state shown in FIG. 8, and the jig 30 is removed.

  7 and 8, the solder 60 interposed between the thicker surface emitting laser 13 and the substrate 50 is more pressed than the solder 60 interposed between the surface emitting laser 12 and the substrate 50. Although it is crushed, the solder 60 is scattered between the surface-emitting laser 13 and the substrate 50 even in the crushed state, and the solder 60 is prevented from adhering to an unexpected place. it can. Further, it becomes difficult to form a sealed hole between the surface emitting lasers 12 and 13 and the solder 60, or between the substrate 50 and the solder 60, and the adhesion between the surface emitting lasers 12 and 13 and the substrate 50 is strengthened. I can do it.

  In the process of FIG. 7, the size of the solder 60 is uniform, but at least one between the surface-emitting laser 12 and the substrate 50 and between the surface-emitting laser 13 and the substrate 50 even if the sizes are different. If the solder 60 is in close contact, the conductivity can be ensured.

  As shown in FIGS. 9 and 11, the substrate side electrode 51 is preferably provided with a groove 51a. The substrate side electrode 52 is similarly provided with a groove, but here, the substrate side electrode 51 will be described. In the structure shown in FIGS. 9 and 11, the groove 51a does not divide the electrode 51, and the electrodes 51 and 52 appear on the bottom surface of the groove 51a.

  A plurality of grooves 51a shown in FIGS. 9 and 11 are provided in a straight line in the width direction (X direction in the drawing) and in the length direction (Y direction in the drawing) orthogonal to the width direction. The shape of the groove 51 a is not limited to the shape shown in FIGS. 9 and 11, but it is preferable that the groove 51 a is formed in a shape that can be removed from at least one side surface 51 b of the electrode 51 (a shape that leads to the side surface 51 b). is there.

  As shown in FIGS. 9 and 11, spherical solder 61 is scattered on the surface 51c (convex surface) of the electrode 51 excluding the groove 51a.

  Then, the solder 61 is melted, and the surface emitting laser 12 and the substrate 50 are brought into close contact with each other through the solder 61 as shown in FIG. At this time, the solder 61 is crushed. In this embodiment, since the electrode 51 appears on the bottom surface of the groove 51a, the groove 51a is also excellent in solder wettability. Therefore, as shown in FIG. 10, a part of the crushed solder 61 escapes into the groove 51a. In this way, the groove 51a can be made to function as an escape groove through which excess solder 61 escapes. Also, by providing the escape groove in this way, when the solder 61 is crushed, air is less likely to collect between the solder 61 and the electrode 51 in a sealed state, and the air can easily escape from the escape groove. .

  After the surface emitting laser 12 and the substrate 50 are brought into close contact with each other through the solder 61, the solder 61 is cured and the surface emitting laser 12 is fixed on the substrate 50.

  Alternatively, as shown in FIG. 12, the electrode 51 may be divided into a plurality of small electrodes 51d by forming the groove 51a. The surface of the substrate 50 appears from the groove 51a.

  As shown in FIG. 12, solder 62 is scattered on the surface of each small electrode 51d. Then, the solder 62 is melted and the surface emitting laser 12 and the substrate 50 are brought into close contact with each other via the solder 62, and then the solder 62 is cured to fix the surface emitting laser 12 on the substrate 50. .

  In FIG. 12, since the surface of the substrate 50 is exposed in the groove 51a between the small electrodes 51d, the solder 62 hardly flows onto the substrate 50 when the solder 62 is crushed. This is because the surface of the substrate 50 has poor solder wettability. However, the groove 51a can function as the air escape described above.

  The structure shown in FIG. 12 is effective when, for example, a solder adhesive containing solder and an organic component (resin) is used as the conductive adhesive. The organic component is provided with a thermosetting resin, for example, and is thermally cured by being separated from the solder by heating. At this time, as shown in FIG. 13, the resin 65 mainly escapes into the groove 51a, while the solder 66 is interposed between the small electrode 51d and the back electrode 33 of the surface-emitting laser 12, and the small electrode 51d and the The back electrodes 33 are joined. In this way, the groove 51 a can function as a relief groove for the resin 65.

  As described above, according to the present embodiment, the light emitting surfaces 12b and 13b of the plurality of surface emitting lasers 12 and 13 attached to the surface emitting laser array 14 can be formed at the same height when viewed from the reference surface.

  Therefore, as shown in FIG. 14, the distances H7 and H8 between the light emitting surfaces 12b and 13b of the plurality of surface emitting lasers 12 and 13 and the principal point 16a of the lens 16 can be made the same. Both the reproduced reference light 22 emitted and the reproduced reference light 71 emitted from the surface emitting laser 13 can be adjusted to parallel light by the lens 16. Therefore, in order to obtain a wavelength at which the hologram data 21 can be reproduced, even if the surface emitting lasers 12 and 13 are switched, reproduction reference beams 22 and 71 having a certain light intensity or more can be obtained with parallel light. 21 can be properly reproduced. As described above, when the hologram reproducing apparatus 10 is manufactured using the surface emitting laser array 14 manufactured according to the present embodiment, the reproduction reference light can be obtained as parallel light having a certain light intensity or more in a wide wavelength band. Therefore, a hologram reproducing device having an excellent hologram reproducing function can be manufactured.

  Incidentally, as shown in FIG. 2, the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13 and the element surface including the entire periphery thereof are formed as a flat surface, or the surface electrode 31 is formed on the light emitting surfaces 12b and 13b. , 32, the surface of the element of the surface emitting lasers 12, 13 is clearly formed as an uneven surface, and the surface of the element may not be formed as a flat surface. . In such a case, when the light emitting surfaces 12b and 13b appear on the convex surface (outermost surface), it is sufficient that the light emitting surfaces 12b and 13b are brought into contact with the facing surface 30a of the jig 30. However, when the light emitting surfaces 12b and 13b appear on the concave surface, the concave surface cannot be brought into contact with the opposing surface 30a. Therefore, the convex surface that is the outermost surface is opposed to the jig 30. It abuts on the surface 30a. In such a case, in each of the surface emitting lasers 12 and 13, in the case where there is some variation in the height dimension between the convex surface and the concave surface, when the manufacturing method of the present embodiment is effective, The variation in the height between the surface of the recesses is reflected as the variation in the height of the light emitting surfaces 12b and 13b of the surface emitting lasers 12 and 13, but in this embodiment, the surface emitting lasers 12 and 13 are compared with the conventional ones. There are no accumulated errors of variations in the height dimensions H3 and H4 and variations in the thickness of the adhesive layer. Therefore, in this embodiment, when the surface emitting lasers 12 and 13 are supported by the jig 30, even when the light emitting surfaces 12 b and 13 b are not strictly adjusted to the same height as described above, the light emitting surfaces 12 b and 12 b By supporting the surface emitting lasers 12 and 13 on the substrate 50 through an adhesive layer in this state, the light emitting surface 12b can be supported as compared with the conventional case. , 13b can be reduced in variation in height. In addition, the variation in the height dimension at this time is about ± 2 μm, and when the variation further spreads, when the surface emitting lasers 12 and 13 are supported on the jig 30, each of the surface emitting lasers 12 and 13 is supported. It is necessary to fix the surface emitting lasers 12 and 13 to the jig 30 with the light emitting surfaces 12b and 13b set to the same height.

  In the embodiment, the number of surface emitting lasers 12 and 13 provided on the substrate 50 is two, but more surface emitting lasers may be mounted. In such a case, when the film thickness of at least one surface emitting laser is different from the film thickness of other surface emitting lasers, it is effective to apply the manufacturing method according to this embodiment.

  In FIG. 7 and subsequent figures, the conductive adhesive is described as solder, but it can also be applied to a conductive paste containing an organic component. In the conductive paste, it is preferable that the organic component is removed by heat treatment at the time of curing.

  In the present embodiment, the hologram reproducing apparatus 10 has been described as an application of the surface emitting laser array 14, but is not limited to the hologram reproducing apparatus. The present invention is applicable to applications where a plurality of surface emitting lasers are used and the light emitting surfaces of the surface emitting lasers are required to have the same height.

  Further, although the surface emitting laser is used as the “light emitting element”, it is not limited to the surface emitting laser.

  Further, in the process of applying a conductive adhesive such as the solder 53 of FIG. 3, the conductive adhesive may be applied to the back electrodes 33 and 34 of the surface emitting lasers 12 and 13, or You may apply | coat to both the said board | substrate side electrodes 51 and 52 and the said back surface electrodes 33 and 34. FIG. However, it is preferable to apply on the substrate side electrodes 51 and 52 because the conductive adhesive can be easily applied.

  Moreover, the form of the said conductive adhesive is not specifically limited, such as a paste form, a film form, and a powder form.

  Further, the method for forming the conductive adhesive on the substrate-side electrodes 51 and 52 is not particularly limited, such as screen printing, an ink jet method, and a sputtering method.

  In the present embodiment, the surface electrodes 31 and 32 are provided on the light emitting surfaces 12 b and 13 b of the surface emitting lasers 12 and 13, but two surfaces are provided on the back surfaces 12 c and 13 c of the surface emitting lasers 12 and 3, respectively. An electrode may be provided. In such a case, each electrode is fixed onto the substrate 50 via a conductive adhesive such as solder.

  Further, the surface emitting lasers 12 and 13 and the substrate 50 are fixed with a conductive adhesive such as solder, which is one reason why the electrodes are electrically connected. Therefore, when it is not necessary to electrically connect the surface emitting lasers 12 and 13 and the substrate 50, an adhesive other than the conductive adhesive can be used.

Conceptual diagram of reproducing hologram data from a recording medium by a hologram reproducing device, 1 process drawing (partial sectional view cut | disconnected from thickness direction) which shows the manufacturing method of the light-emitting device (surface emitting laser array) in this embodiment, One process diagram (partial sectional view cut from the thickness direction) performed next to FIG. One process diagram (partial sectional view cut from the thickness direction) performed next to FIG. One process diagram (partial sectional view cut from the thickness direction) performed after FIG. 2 is a partial plan view of the surface emitting laser and jig shown in FIG. 1 process drawing which shows a preferable example of the manufacturing method of the light-emitting device in this embodiment (it is a process drawing which replaces the process of FIG. 3, and is a partial expanded sectional view expanded and shown compared with FIG. 3), FIG. 7 is a process diagram that is performed next to the process diagram (a process diagram in place of the process in FIG. FIG. 9 is a process diagram showing a preferred example of a method for manufacturing a light emitting device according to the present embodiment (FIG. 9 is a view of the substrate and adhesive (solder) cut in the thickness direction along the line AA shown in FIG. ) Partial enlarged sectional view of FIG. 9 is a process diagram subsequent to FIG. 9 (partial enlarged cross-sectional view of the substrate, surface emitting laser and adhesive (solder) showing a state where the surface emitting laser and the substrate are joined after the step of FIG. 9); The partial enlarged plan view which looked at the board | substrate and adhesive agent (solder) shown in FIG. 9 from right above, FIG. 11 is a partially enlarged plan view of the substrate and the adhesive (solder) showing the shape of the substrate different from FIG. FIG. 12 is a partial cross-sectional view of the substrate in which a surface emitting laser is bonded to the substrate shown in FIG. 12, the adhesive (solder), and the surface emitting laser are cut from the thickness direction (the cutting position is one step before the step in FIG. 13). 12 is a BB line shown in Fig. 12. The partial cross-sectional view of Fig. 13 is cut along the BB line in the filming direction and viewed from the arrow direction), The conceptual diagram for demonstrating the irradiation state of the reproduction | regeneration reference light irradiated from each surface emitting laser, incorporating the surface emitting laser array manufactured by the manufacturing method by this embodiment in a hologram reproduction apparatus, The conceptual diagram which shows the irradiation state of the reproduction | regeneration reference light irradiated from each surface emitting laser for demonstrating the conventional problem,

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hologram reproducing | regenerating apparatus 12, 13 Surface emitting laser 12b, 13b Light emitting surface 14 Surface emitting laser array 17 Lens array 18 Image pick-up element 19 Pinhole filter 20 Recording medium 21 Hologram data 22, 71 Reproduction reference light 23 Reproduction light 30 Jig 30a Opposite Surface 33 Back electrode (light emitting element side electrode)
40, 41 Mark part 50 Substrate 51 Substrate side electrode 51a Groove 53, 60, 61, 62, 66 Solder (conductive adhesive)
54 Base 57 Wire 65 Resin C Coplanar

Claims (9)

In a method for manufacturing a light emitting device in which a plurality of light emitting elements are provided on a substrate,
With the light emitting surfaces of the plurality of light emitting elements being adjusted to the same height on the substrate, the light emitting elements are adhered to the substrate via an adhesive,
Then, the said adhesive agent is hardened | cured and the said light emitting element is fixed on the said board | substrate, The manufacturing method of the light-emitting device characterized by the above-mentioned.   A plurality of the light emitting elements are attached to a jig, the light emitting surfaces are set to the same height, and the light emitting elements are adhered to the substrate via an adhesive while maintaining the same height, and the adhesive is cured. The method of manufacturing a light emitting device according to claim 1, wherein the jig is removed after the step. The manufacturing method of the light-emitting device of Claim 2 which has the following processes.
(A) The light emitting element is prepared in a state in which the light emitting surface is opposed to the light emitting surface, the jig having the same plane formed thereon, and the light emitting surfaces of the plurality of light emitting elements in contact with the same plane. Fixing to the jig;
(B) The jig is opposed to the substrate, and at this time, the light emitting surfaces of the plurality of light emitting elements are matched to the same height, and the gap between the substrate and the light emitting elements is maintained while maintaining the same height. Adhering via the adhesive;
(C) curing the adhesive and fixing the light emitting element on the substrate;
(D) A step of releasing the fixed state between the light emitting element and the jig and removing the jig. In a method for manufacturing a light emitting device in which a plurality of light emitting elements are provided on a substrate,
A jig is prepared in which opposing surfaces facing the respective light emitting surfaces of the plurality of light emitting elements are formed on the same plane, and each light emitting element is brought into contact with the same plane of the jig from the light emitting surface side. In a state of being fixed to, the light emitting element is closely attached to the substrate via an adhesive,
Then, the adhesive is cured, the light emitting element is fixed on the substrate, the fixing state between the light emitting element and the jig is released, and the jig is removed. Device manufacturing method.   Electrodes are provided on the surface opposite to the light emitting surface of the light emitting element and the surface of the substrate, respectively, and a groove is formed in at least one of the light emitting element side electrode and the substrate side electrode. The method for manufacturing a light-emitting device according to claim 1, wherein the adhesive is provided on the electrode excluding the electrode.   Electrodes are provided on the surface opposite to the light emitting surface of the light emitting element and the surface of the substrate, respectively, and a conductive adhesive is used as the adhesive, and the light emitting element side electrode and the substrate side are provided. The method for manufacturing a light-emitting device according to claim 1, wherein electrodes are electrically connected to each other via the conductive adhesive.   The method for manufacturing a light emitting device according to claim 6, wherein solder is used for the conductive adhesive.   The method for manufacturing a light-emitting device according to claim 6, wherein a conductive paste containing an organic component is used as the conductive adhesive, and the organic component is removed by heat treatment when the conductive adhesive is cured.   The method for manufacturing a light emitting device according to claim 1, wherein the adhesive is scattered between each light emitting element and the substrate.

Images