JP2017037927A - Optical module and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an optical module in which the possibility that foreign substances adhere to an optical element is low, and the possibility that foreign substances having probability adhering to an optical element are present in a housing is also low.SOLUTION: An optical module includes: a housing (110) including a side wall (111) having a support part (111a) formed to an inner side face (111d), a bottom plate (112) joined to a lower end face (111e) of the side wall (111), and a lid (113) joined to an upper end face (111f) of the side wall (111); and an optical element (120) placed to the support part (111a). A gap (130) is formed between the optical element (120) and the inner side face (111d) of the side wall (111).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical module in which an optical element is stored in a casing. Moreover, it is related with the manufacturing method of such an optical module.

  Optical elements capable of controlling the emission direction of reflected light, such as LCOS (Liquid Crystal On Silicon) elements and MEMS (Micro Electro Mechanical System) elements, have been put into practical use. Since such an optical element can be used as an optical switch that emits incident light from a selected output port, application to RODAM (Reconfiguration Optical Add / Drop Multiplexer) technology is possible.

  In such an optical element, it is necessary to avoid as much foreign matter as possible from adhering to the effective region that assumes the reflection function. This is because adhesion of foreign matter to the effective region causes problems such as occurrence of crosstalk and deterioration of the SN ratio in optical communication using such an optical element.

  As a technique that may contribute to the solution of such a problem, for example, an image sensor described in Patent Document 1 may be cited. The image sensor described in Patent Literature 1 is an optical module in which optical elements such as a Selfoc lens array and a photodiode array are housed in a casing. In the image sensor described in Patent Literature 1, the optical path from the Selfoc lens array to the photodiode array is filled with an epoxy resin to prevent entry of foreign matter into the optical path.

JP 7-135547 (release date: May 23, 1995)

  As an optical module casing, a two-part configuration is generally used which includes a casing main body in which a bottom plate and a side wall are integrated, and a lid that closes an opening of the casing main body. The lid is provided with a window for transmitting light input to the effective area of the optical element and / or light output from the effective area of the optical element.

  When the technique described in Patent Document 1 is applied to an optical module having such a housing, the optical path from the effective area of the optical element to the window portion of the lid is filled with epoxy resin. However, in view of the manufacturing method of the optical module having such a housing, it is difficult to fill the optical path from the effective area of the optical element to the window portion of the lid with an epoxy resin.

  That is, as a manufacturing method of such an optical module, (1) after fixing an optical element to a housing body and then sealing the housing body with a lid, and (2) after fixing an optical element to the lid And a method of sealing the housing body with a lid. However, when the latter method is adopted, the positional relationship between the optical element and the housing body is determined when the sealing is completed. Accordingly, it is difficult to connect the optical element and the housing body with a wire, which should be performed after the positional relationship between the optical element and the housing body is determined. For this reason, since the latter method cannot be adopted, the former method is adopted. However, when the former method is adopted, the positional relationship between the optical element and the lid is determined when the sealing is completed. Therefore, it becomes difficult to fill the space between the effective area of the optical element and the window portion of the lid with the epoxy resin, which should be performed after the positional relationship between the optical element and the lid is determined. For this reason, it is impossible to avoid the adhesion of dust to the optical element by applying the technique described in Patent Document 1.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to reduce the possibility that foreign matters are attached to the optical element, and foreign matters that may be attached to the optical element are present in the housing. The object is to realize an optical module that is unlikely to exist.

  In order to achieve the above object, an optical module according to the present invention includes a housing having a side wall, a bottom plate joined to the lower end surface of the side wall, and a lid joined to the upper end surface of the side wall; An optical element supported by a support portion provided on an inner surface, and a gap is formed between the optical element and the inner surface of the side wall.

  According to said structure, (1) The said optical element is fixed to the support part formed in this inner surface so that a clearance gap may be formed between the said optical element and the inner surface of the side wall of the said housing | casing. A fixing step, (2) a removal step of removing foreign matter adhering to the optical element, (3) a step of joining the bottom plate of the housing to the lower end surface of the side wall, and (4) an upper end surface of the side wall. An optical module can be manufactured by the joining step of joining the lid of the casing. And in the said removal process, the foreign material removed from the said optical element can be discharged | emitted out of a housing | casing through the said clearance gap. For this reason, the foreign material adhering to the said optical element can be removed, without leaving a foreign material in a housing | casing at the time of manufacture of an optical module.

  Therefore, according to the above configuration, the optical module is unlikely to have foreign matter attached to the optical element and has low possibility of foreign matter that may adhere to the optical element in the housing. Can be realized.

  The optical module which concerns on this invention WHEREIN: It is preferable that the said support part is comprised by the some convex part formed in the inner surface of the said side wall.

  According to said structure, support of the said optical element is realizable with a simple structure.

  In the optical module according to the present invention, the inner surface includes a first surface, a second surface that intersects with the first surface, a third surface that intersects with the second surface and faces the first surface, and the first surface. And a fourth surface that intersects with the third surface and faces the second surface, and the support portion is formed on the second surface, and one end portion of the optical element is A first convex portion supported from the second surface side, a second convex portion formed on the second surface and supporting the other end portion of the optical element from the second surface side, and the fourth surface It is preferable that the third convex portion is formed and configured to support the central portion of the optical element from the fourth surface side.

  According to the above configuration, the three-point support of the optical element can be realized with a simple configuration.

  In the optical module according to the present invention, it is preferable that the optical element is separated from the bottom plate.

  In an optical element that requires temperature control (for example, an LCOS element), the optical element may include a heater. In such a case, according to said structure, it can prevent that the heat from a heater escapes to the said baseplate.

  In order to achieve the above object, an optical module manufacturing method according to the present invention is an optical module manufacturing method including a housing and an optical element, and includes an inner surface of the optical element and a side wall of the housing. A fixing step of fixing the optical element to a support portion formed on the inner surface so that a gap is formed between the two, and a removing step of removing foreign matter adhering to the optical element after the fixing step And a bottom plate joining step for joining the bottom plate of the housing to the lower end surface of the side wall after the removing step; and after the removing step, before or after the bottom plate joining step, the housing on the upper end surface of the side wall. And a lid joining step for joining body lids.

  According to the above configuration, an optical module is manufactured that has a low possibility of foreign matter adhering to the optical element and that is unlikely to contain foreign matter that may adhere to the optical element. It becomes possible.

  In the method for manufacturing an optical module according to the present invention, it is preferable that the removing step removes the foreign matter attached to the optical element using a wind that blows through the space surrounded by the side wall through the gap.

  According to the above configuration, an optical module in which the possibility that foreign matter is attached to the optical element is further lower and the possibility that foreign matter that may be attached to the optical element is present in the housing is further reduced. It becomes possible to manufacture.

  According to the present invention, it is possible to realize an optical module that is unlikely to have foreign matter attached to an optical element and that is unlikely to have foreign matter that may be attached to the optical element. Can do.

It is a perspective view of the optical module which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical module which concerns on Embodiment 1 of this invention. It is a top view of the optical module which concerns on Embodiment 1 of this invention. It is a figure which shows each process of the manufacturing method of the optical module which concerns on Embodiment 1 of this invention. It is a top view of the 1st modification of the optical module which concerns on Embodiment 1 of this invention. It is a top view of the 2nd modification of the optical module which concerns on Embodiment 1 of this invention. It is sectional drawing of the optical module which concerns on Embodiment 2 of this invention.

Embodiment 1
(Configuration of optical module)
The configuration of the optical module 100 according to the present embodiment will be described with reference to FIGS. 1 is a perspective view showing the appearance of the optical module 100, FIG. 2 is a cross-sectional view showing a cross section of the optical module 100, and FIG. 3 is a top view showing a state in which the lid 113 of the optical module 100 is removed. FIG.

  As illustrated in FIGS. 1 to 2, the optical module 100 includes a housing 110 and an optical element 120 stored in the housing 110.

  The housing 110 is configured to store the optical element 120. As shown in FIG. 2, the side wall 111, the bottom plate 112 whose outer periphery (of the bottom plate 112) is joined to the lower end surface of the side wall 111, and its The outer periphery (of the lid 113) has a lid 113 joined to the upper end surface of the side wall 111. As shown in FIG. 1, in the present embodiment, a rectangular parallelepiped shape (rounded edges) having a rectangular bottom plate 112 (with rounded corners) and a lid 113 as a casing 110 in the present embodiment. A box-shaped housing is used.

  The side wall 111 is a plate-like member that surrounds a space for storing the optical element 120 from four directions, and is made of, for example, ceramic. As shown in FIG. 2, a metal seal ring 111b is formed on the lower end surface 111e of the side wall 111 along the inner periphery thereof. The seal ring 111 b is used for seam welding the bottom plate 112 to the side wall 111. Similarly, a seal ring 111c is formed on the upper end surface 111f of the side wall 111 along the inner periphery thereof as shown in FIGS. This seal ring 111 c is used for seam welding the lid 113 to the side wall 111. A support portion 111 a for supporting the optical element 120 is formed on the inner side surface 111 d of the side wall 111. In the present embodiment, as shown in FIGS. 2 to 3, flat plate-like convex portions 111 a 1 and 111 a 2 having a rectangular shape in plan view are used as the support portions 111 a.

  In the present embodiment, the outer shape of the housing 110 is a rectangular parallelepiped shape. Therefore, as shown in FIG. 3, the inner surface 111d of the side wall 111 includes (1) a first plane (first surface) 111d1 and (2) a second plane (second surface) orthogonal to the first plane 111d1. 111d2, (3) a third plane (third surface) 111d3 that is orthogonal to the second plane 111d2, and that faces the first plane 111d1, and (4) a second plane that is orthogonal to the first plane 111d1 and the third plane 111d3. And a fourth plane (fourth surface) 111d4 facing the plane 111d2. The first flat convex portion 111a1 constituting the support portion 111a is provided at the center of the first plane 111d1 so that the upper surface thereof is parallel to the bottom plate 112, and supports one end of the optical element 120 from below. To do. In addition, the second flat plate-shaped convex portion 111a2 constituting the support portion 111a is provided at the center portion of the third plane 111d3 so that the upper surface thereof is parallel to the bottom plate 112, and the other end portion of the optical element 120 is placed below the second flat portion. Support from. These two flat projections 111a1 and 111a2 are arranged so that the heights of the upper surfaces thereof are aligned so that the optical element 120 can be placed in parallel with the bottom plate 112.

  The bottom plate 112 is a plate-like member for closing a space surrounded on all sides by the side wall 111 from below, and is made of, for example, metal. As shown in FIG. 2, the outer periphery of the upper surface of the bottom plate 112 is joined to the lower end surface 111 e of the side wall 111. Specifically, the outer periphery of the upper surface is seam welded to a seal ring 111 b formed on the lower end surface 111 e of the side wall 111.

  The lid 113 is configured to close the space surrounded by the side wall 111 from above, and as shown in FIGS. 1 to 2, the frame-shaped frame portion 113a and the lower surface of the frame portion 113b (of the window portion 113b) The outer periphery has a plate-like window portion 113b joined to the inner periphery of the upper surface of the frame portion 113a. The frame 113a is made of metal, and its outer periphery is joined to the upper end surface 111f of the side wall 111 as shown in FIG. Specifically, the outer periphery of the lower surface is seam welded to a seal ring 111 c formed on the upper end surface 111 f of the side wall 111. The window 113b is made of a transparent material such as quartz glass, and transmits light that enters or exits the optical element 120.

  The optical element 120 is an element having an optical function such as a reflection function, a light reception function, or a light emission function. An effective area 124 is formed on the surface of the optical element 120. Here, the effective region 124 refers to a region that assumes an optical function in the optical element 120, for example, a reflective region in the reflective element, a light receiving region in the light receiving element, or a light emitting region in the light emitting element.

  In the present embodiment, as shown in FIG. 2, an LCOS (Liquid Crystal On Silicon) element constituted by a silicon substrate 121, a liquid crystal 122, and a cover glass 123 is used as the optical element 120. The LCOS element is a reflection element capable of controlling the emission direction of reflected light from the outside. An electric signal for controlling the emission direction of the reflected light is supplied through a wire 125 bonded to the silicon substrate 121. As shown in FIGS. 2 to 3, the wire 125 is connected to an electrode penetrating the housing 110, and an electric signal from the outside of the optical module 100 is input to the optical element 120, or from the optical element 120. It is possible to output an electrical signal to the outside of the optical module 100. Note that, in the LCOS element, the surface of the cover glass 123 covering the liquid crystal 122 becomes an effective region 124 having a reflection function.

  The optical element 120 is supported by the support portion 111 a formed on the inner side surface 111 d of the side wall 111 so that the effective region 124 faces the window portion 113 b of the lid 113. In this embodiment, as shown in FIGS. 2 to 3, (1) one of the optical elements 120 is formed by the first flat plate-shaped protrusion 111 a 1 formed on the first flat surface 111 d 1 constituting the inner surface 111 d of the side wall 111. (2) The other end of the optical element 120 is supported by the second flat plate-shaped convex portion 111a2 formed on the third flat surface 111d3 constituting the inner surface 111d of the side wall 111. The optical element 120 is fixed (for example, adhesively fixed) to these two flat projections 111a1 and 111a2, and the position in the housing 110 is not changed.

  Further, the outer dimension of the optical element 120 is smaller than the inner diameter dimension of the housing 110, and a gap 130 is formed between the optical element 120 and the inner side surface 111 d of the side wall 111. In the present embodiment, (1) a first gap 131 is formed between the second flat surface 111 d 2 constituting the inner side surface 111 d of the side wall 111, and (2) a fourth flat surface constituting the inner side surface 111 d of the side wall 111. A second gap 132 is formed between 111d4. The gap 130 is used to remove foreign matters attached to the optical element 120 during the manufacturing process of the optical module 100.

  In the present embodiment, a box-shaped casing having a rectangular parallelepiped shape and having a rectangular bottom plate 112 in plan view is used as the casing 110. However, the shape of the bottom plate 112 in plan view is not particularly limited, and the outer shape of the housing 110 may be a column shape. For example, the casing 110 may be a bowl-shaped casing having a circular bottom plate 112 having a circular shape in plan view.

  In the present embodiment, an LCOS element that is a reflective element is used as the optical element 120. However, the optical element 120 is not limited to this. For example, another reflective element such as a MEMS (Micro Electro Mechanical System) element may be used as the optical element 120, a light emitting element such as an LD (Laser Diode) may be used as the optical element 120, or a PD (Photo A light receiving element such as a diode may be used as the optical element 120.

  In the present embodiment, as a method for supporting the optical element 120, the support portion 111a is configured by two flat plate-like convex portions 111a1 and 111a2, and the optical element 120 is placed on the two flat plate-like convex portions 111a1 and 111a2. The support method is adopted. However, the support method of the optical element 120 is arbitrary and is not limited to this. Moreover, the form of the support part 111a should just be according to the support method of the optical element 120, and is not limited to this. In the present embodiment, the gap between the optical element 120 and the inner side surface 111d is a gap between the first plane 131d between the second plane 111d2 and the fourth plane 111d4. A second gap 132 is provided. However, the number of the gaps 130 and the positions of the gaps 130 are arbitrary and are not limited thereto. For example, the gap 130 may be one place, or may be three or more places.

(Optical module manufacturing method)
Next, a method for manufacturing the optical module 100 will be described with reference to FIG. The manufacturing method of the optical module 100 includes (1) a step 1 for fixing the optical element 120 to the support portion 111a formed on the inner surface 111d of the side wall 111, (2) a step 2 for wiring the wire 125 to the optical element 120, 3) Step 3 for removing foreign matter adhering to the optical element 120, (4) Step 4 for joining the lid 113 to the upper end surface 111f of the side wall 111, and (5) Joining the bottom plate 112 to the lower end surface 111e of the side wall 111. Step 5 is included. 4A to 4F are cross-sectional views of the optical module 100 before and after performing each step.

<Step 1>
The optical element 120 is fixed to the support portion 111a provided on the inner side surface 111d so that a gap 130 is formed between the optical element 120 and the inner side surface 111d of the side wall 111. Specifically, an adhesive is applied to the upper surfaces of the plate-like convex portions 111a1 and 111a2 constituting the support portion 111a, and the optical element 120 is placed on the upper surfaces of the plate-like convex portions 111a1 and 111a2, and then the adhesive is applied. Harden. FIG. 4A shows a state before this step is performed, and FIG. 4B shows a state after this step is performed.

<Process 2>
After step 1, a wire 125 is wired to the optical element 120. Specifically, after the wire 125 is passed through the through hole provided in the side wall 111, the tip of the wire 125 is bonded to the electrode of the optical element 120. FIG. 4B shows a state before this step is performed, and FIG. 4C shows a state after this step is performed. In FIG. 4C, a foreign substance 140 such as dust attached to the surface of the optical element 120 in this step is schematically shown by a black diamond.

<Step 3>
After step 2, the foreign material 140 attached to the optical element 120 is removed. Specifically, the foreign material 140 attached to the optical element 120 is dropped downward using a wind that blows through a space surrounded by the side wall 111 such as air blow. A space surrounded by the side wall 111 because the gap 130 is formed between the optical element 120 and the inner side surface 111d of the side wall 111, and the lid 113 and the bottom plate 112 are not yet assembled in this step. The foreign matter 140 can be removed using the wind that blows through the air. FIG. 4C shows a state before this step is performed, and FIG. 4D shows a state after this step is performed.

<Step 4>
After step 3, the lid 113 is joined to the upper end surface 111f of the side wall 111. Specifically, the outer periphery of the frame portion 113 a of the lid 113 is seam welded to a seal ring 111 c formed on the upper end surface 111 f of the side wall 111.

<Step 5>
After step 4, the bottom plate 112 is joined to the lower end surface 111e of the side wall 111. Specifically, the outer periphery of the bottom plate 112 is seam welded to a seal ring 111 b formed on the lower end surface 111 e of the side wall 111.

  Note that the order in which step 4 and step 5 are performed may be reversed. That is, the lid 113 may be joined to the side wall 111 after the bottom plate 112 is joined to the side wall 111. Further, in step 4 and step 5, the bottom plate 112 and the lid 113 are welded by seam welding, but the welding method is not limited to seam welding, and may be laser welding, for example. Moreover, when performing the process 4 and the process 5 in this order, it is preferable to start the process 5 simultaneously with completion | finish of the process 4 (it implements the process 4 and the process 5 continuously), and the process 4 and the process 5 When the steps are performed in the reverse order, it is preferable that the step 4 is started simultaneously with the end of the step 5 (the step 5 and the step 4 are continuously performed). Thereby, it is possible to prevent foreign matter from entering the housing 110 during the period from the end of step 4 to the start of step 5 or during the period from the end of step 5 to the start of step 4.

[Modification 1]
A first modification of the optical module 100 according to the present embodiment will be described with reference to FIG. FIG. 5 is a top view showing the configuration of the optical module 100 according to this modification.

  The optical module 100 according to this modification is different from the optical module 100 shown in FIG. 3 in the form of a support portion 111a provided in the housing 110.

  In the optical module 100 according to this modification, the optical element 120 is composed of the first flat plate-shaped convex portion 111a1 ′, the second flat plate-shaped convex portion 111a2 ′, and the third flat plate-shaped convex portion 111a3 ′. I support it. The first flat projection 111a1 'is provided near the first plane 111d1 of the second plane 111d2 so that the upper surface thereof is parallel to the bottom plate 112, and supports the optical element 120 from below. The second flat plate-shaped convex portion 111a2 'is provided near the third plane 111d3 of the second plane 111d2 so that the upper surface thereof is parallel to the bottom plate 112, and supports the optical element 120 from below. The third flat plate-shaped protrusion 111a3 'is provided at the center of the fourth plane 111d4 so that the upper surface thereof is parallel to the bottom plate 112, and supports the optical element 120 from below. These three flat projections 111 a 1 ′, 111 a 2 ′, and 111 a 3 ′ are arranged so that the heights of the upper surfaces thereof are aligned so that the optical element 120 is placed in parallel with the bottom plate 112.

  Also in this modified example, a gap 130 is formed at a place where the support portion 111 a between the optical element 120 and the inner surface 111 d of the side wall 111 is not formed.

[Modification 2]
A second modification of the optical module 100 according to the present embodiment will be described with reference to FIG. FIG. 6 is a top view showing the configuration of the optical module 100 according to this modification.

  The optical module 100 according to this modification is different from the optical module 100 shown in FIG. 3 in the form of a support portion 111a provided in the housing 110.

  In the optical module 100 according to this modification, the optical element 120 includes the first flat plate-shaped convex portion 111a1 ″, the second flat plate-shaped convex portion 111a2 ″, the third flat plate-shaped convex portion 111a3 ″, and The fourth flat convex portion 111a4 ″ is supported at four points. The first flat plate-shaped protrusion 111a1 ″ is provided at the center of the first plane 111d1 so that the upper surface thereof is parallel to the bottom plate 112, and supports one end of the optical element 120 from below. Further, the second flat plate-shaped convex portion 111a2 ″ is provided at the center of the third plane 111d3 so that the upper surface thereof is parallel to the bottom plate 112, and supports the other end of the optical element 120 from below. The third flat plate-shaped protrusion 111a3 '' is provided at the center of the second plane 111d2 so that the upper surface thereof is parallel to the bottom plate 112, and supports one side end of the optical element 120 from below. . The fourth flat convex portion 111a4 '' is provided at the center of the fourth plane 111d4 so that the upper surface thereof is parallel to the bottom plate 112, and supports the other side end portion of the optical element 120 from below. . These four flat projections 111a1 ″, 111a2 ″, 111a3 ″, and 111a4 ″ are arranged so that the height of the upper surface is aligned so that the optical element 120 is placed in parallel with the bottom plate 112. Yes.

  Also in this modified example, a gap 130 is formed at a place where the support portion 111 a between the optical element 120 and the inner surface 111 d of the side wall 111 is not formed.

[Embodiment 2]
An optical module 100 ′ according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view showing the configuration of the optical module 100 ′ according to this embodiment.

  The optical module 100 ′ includes a housing 110 and an optical element 120 ′. The casing 110 included in the optical module 100 ′ is configured similarly to the casing 110 included in the optical module 100 according to the first embodiment. On the other hand, the optical element 120 ′ included in the optical module 100 ′ is an LCOS element similar to the optical element 120 included in the optical module 100 according to the first embodiment, but its shape is different from that of the optical element 120. ing.

  That is, in the optical element 120 ′ included in the optical module 100 ′, the longitudinal dimension of the cover glass 123 is longer than the longitudinal dimension of the silicon substrate 121. For this reason, in this embodiment, the lower surface of the silicon substrate 121 is not placed on the support portion 111a, but the lower surface of the cover glass 123 is placed on the support portion 111a.

  Also in the present embodiment, the outer dimension of the optical element 120 ′ is smaller than the inner diameter dimension of the housing 110, and a gap 130 is formed between the optical element 120 ′ and the inner surface 111 d of the side wall 111. For this reason, as in the optical module 100 according to the first embodiment, the foreign matter adhering to the optical element 120 ′ can be easily removed during the manufacturing process of the optical module 100 ′.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

100, 100 'Optical module 110 Housing 111 Side wall 111a Support portion 111a1, 111a1', 111a1 '' First flat plate-shaped convex portion 111a2, 111a2 ', 111a2''Second flat plate-shaped convex portion 111a3', 111a3 '' 3rd flat plate-like convex part 111a4 '' 4th flat plate-like convex part 111d inner surface 111d1 1st plane (1st surface)
111d2 2nd plane (2nd surface)
111d3 third plane (third surface)
111d4 fourth plane (fourth surface)
112 Bottom plate 113 Lid 113a Frame portion 113b Window portion 120, 120 ′ Optical element 124 Effective area 130 Gap 131 First gap 132 Second gap 140 Foreign matter

Claims (6)

A side wall, a bottom plate joined to the lower end surface of the side wall, a housing having a lid joined to the upper end surface of the side wall, and an optical element supported by a support portion provided on the inner side surface of the side wall. Prepared,
An optical module, wherein a gap is formed between the optical element and the inner side surface of the side wall. The support portion is configured by a plurality of convex portions formed on the inner side surface of the side wall.
The optical module according to claim 1. The inner surface includes a first surface, a second surface that intersects with the first surface, a third surface that intersects with the second surface and faces the first surface, the first surface, and the third surface. And a fourth surface facing the second surface,
The support portion is formed on the second surface, and is formed on the second surface with a first convex portion that supports one end portion of the optical element from the second surface side, and the other end of the optical element. The second convex portion that supports the end portion from the second surface side, and the third convex portion that is formed on the fourth surface and supports the central portion of the optical element from the fourth surface side. The optical module according to claim 2. The optical element is spaced apart from the bottom plate;
The optical module according to any one of claims 1 to 3, wherein: A method of manufacturing an optical module comprising a housing and an optical element,
A fixing step of fixing the optical element to a support portion formed on the inner surface such that a gap is formed between the optical element and the inner surface of the side wall of the housing;
After the fixing step, a removing step for removing foreign matters attached to the optical element;
After the removing step, a bottom plate joining step for joining the bottom plate of the housing to the lower end surface of the side wall;
After the removing step, before or after the bottom plate joining step, a lid joining step for joining the lid of the housing to the upper end surface of the side wall,
The manufacturing method characterized by the above-mentioned.   The manufacturing method according to claim 5, wherein the removing step removes foreign matter attached to the optical element by using a wind that blows through a space surrounded by the side wall through the gap.

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