JP2010122311A - Lens block and optical module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens block that facilitates mounting and has high reliability. <P>SOLUTION: The lens block 4 includes: a lens 4G on the side of an optical transmission line optically connected to an outside optical transmission line 5; a lens 4E on the side of an optical element optically connected to an optical element 3; and a reflection part 14 that transforms the optical axis of the lens 4G on the optical transmission line side at an angle of 90° to make it coincident with the optical axis of the lens 4E on the optical element side. In the periphery of the lens 4E on the optical element side, there is formed a projecting wall 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens block for optical communication and an optical module using the same.

  In recent years, the Internet has been established as a communication infrastructure, and various types of industries and services have been taken in regardless of the type of information such as data communication, voice, and video, and its application range continues to expand. In line with this, the line capacity has been steadily increasing.

  At present, standardization of 10 Gigabit Ethernet (registered trademark) has been completed, and network devices for 10 Gigabit have been developed by various companies. As a result, optical transceivers (optical modules) used in network devices are also An upgrade from a transmission rate of 1 Gbps to 10 Gbps has started mainly in a distance network. In addition, development and research of 40 to 100 Gbps class Ethernet (registered trademark) whose transmission rate exceeds 10 Gbps has started. Under such circumstances, there is a demand for an optical module that can cope with further increase in the number of channels, speed, and size.

  An optical module that supports multi-channel, high-speed, and miniaturization is equipped with an optical element that transmits or receives multiple optical signals on a circuit board, and a lens block that has a lens array facing the optical element. In general, a mounting structure in which a ferrule having an optical fiber inserted therein is connected to the lens block.

  The prior art document information related to the invention of this application includes the following.

JP 2005-92120 A JP 2004-138882 A

  The alignment between the lens array and the plurality of optical elements needs to be accurately performed for optical coupling between the lens array and the optical elements.

  However, in the conventional optical module, it is very difficult and time-consuming to align the optical element and the lens block at the time of mounting.

  Accordingly, an object of the present invention is to provide a lens block that is easy to mount and has high reliability, and an optical module using the same.

  Invented to achieve the above object, the present invention provides an optical transmission path side lens portion optically connected to an external optical transmission path, an optical element side lens portion optically connected to an optical element, In a lens block including a reflection unit that converts the optical axis of the optical transmission path side lens unit by 90 ° and matches the optical axis of the optical element side lens unit, the optical element side lens unit and / or the optical transmission path side lens unit This is a lens block having a projection wall formed around it.

  Further, the present invention provides a light comprising the lens block, a first substrate on which a fitting hole for fitting with a projection wall of the lens block is formed, and a second substrate on which an electric signal circuit is formed. In the module, the optical element and the electronic element are disposed on the first substrate, and the optical element and the electronic element disposed on the first substrate are exposed on the second substrate. The through-hole is formed, and the second substrate is disposed on a surface opposite to the surface of the first substrate on which the lens block is mounted.

  The fitting hole of the first substrate is a portion where the hole diameter of the portion near the optical element side lens portion and / or the optical transmission path side lens portion is farther than the optical element side lens portion and / or the optical transmission path side lens portion. It is good that it is larger than the hole diameter.

  Furthermore, the present invention provides a light comprising the above-described lens block, a first substrate on which a fitting hole for fitting with a projection wall of the lens block is formed, and a second substrate on which an electric signal circuit is formed. In the module, an electronic element is disposed on the first substrate, and a through hole for exposing the electronic element disposed on the first substrate is formed on the second substrate, The second substrate is disposed on a surface opposite to the surface of the first substrate on which the lens block is mounted, the fitting hole of the first substrate has a single hole diameter, and the fitting In the optical module, the second substrate is disposed at a position facing the hole, and the optical element is disposed at a position facing the fitting hole of the second substrate.

  The first substrate may be made of a ceramic substrate or a Si substrate.

  According to the present invention, it is possible to realize a lens block that is easy to mount and highly reliable.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  FIG. 1A is a longitudinal sectional view of an optical module using a lens block showing a preferred first embodiment of the present invention, FIG. 1B is a perspective view thereof, and FIG. 2 is FIG. FIG. 3 is an exploded perspective view in which the lens block is exploded from the bottom side, and FIG. 3 is an exploded perspective view in which the lens block is exploded from FIG.

  As shown in FIGS. 1-3, the optical module 1 which concerns on this embodiment is the mounting structure of the principal part which bears the photoelectric conversion function of the optical module later mentioned in FIG. 4, for example.

  The optical module 1 includes a circuit board 2 (“second board”), an optical element 3 that transmits or receives a plurality of optical signals, and a lens block that is optically coupled to face the optical element 3. 4, a ferrule 6 in which an optical fiber 5 optically coupled to the lens block 4 is connected, a lens block 4 is mounted, and a holding substrate 7 that holds a part of the lens block 4 (“first Substrate ").

  The entire circuit board 2 is formed in a substantially strip shape. On the circuit board 2, an electric signal circuit composed of wiring and electronic parts for mounting an electric signal for driving the transmitting optical element and an electric signal from the receiving optical element is mounted.

  A through hole 10 is formed in the center of one end of the circuit board 2 for exposing the optical element 3 disposed on the holding substrate 7 and the IC chip 11 as an electronic element. The through hole 10 is formed so that both the optical element 3 and the IC chip 11 can be accommodated side by side.

  As the circuit board 2, a flexible printed board (FPC), a rigid board, or a flexible rigid board is used. In the present embodiment, as the circuit board 2, a flexible printed board having a high degree of freedom in mounting components and placing the board in the optical module is used.

  As the optical element 3, a transmitting optical element array in which a plurality of semiconductor laser (LD) elements are arranged in parallel or a receiving optical element array in which a plurality of photodiode (PD) elements are arranged in parallel are used. . There is a VCSEL (surface emitting laser) array as an optical element array for transmission.

  The lens block 4 is formed in an approximately L shape in a side view, and the incident direction and the outgoing direction of the optical signal are different from each other by 90 ° (intersect at right angles), and is also referred to as a right angle lens array.

  At the center of the bottom surface 4d, which is the surface on the optical element side of the lens block 4, an optical element side lens array 4E that protrudes greatly downward on the optical element side is formed as an optical element side lens part. Here, the term “largely projecting downward” means that the optical element side lens array 4E protrudes downward (on the optical element 3 side) from the bottom surface 4d in contact with the counterpart member (here, the holding substrate 7). . In a general lens array, each lens is formed so as to be away from the surface in contact with the other side (the back side of its own lens block).

  The optical element side lens array 4E collimates a plurality of optical signals emitted from the optical element 3 and enters the lens block 4, or outputs a plurality of optical signals emitted from the lens block 4 toward the optical element 3, respectively. A plurality of (12 in FIG. 2) optical element side lenses 4e for condensing are arranged in parallel in the width direction of the lens block 4 (in FIG. 1A, the direction perpendicular to the paper surface).

  A projection wall 22 is formed around the optical element side lens array 4E as a part of the lens block 4 fitted to the holding substrate 7. In the present embodiment, a linear side wall 22s formed on both sides of the optical element side lens array 4E along the lens arrangement direction with a space therebetween, and an arc-shaped connection wall 22c connecting the side walls 22s. A substantially elliptic cylindrical projection wall 22 is used. Since the protruding wall 22 may be anything that surrounds the optical element side lens array 4E with a space therebetween, it may have a rectangular tube shape or a discontinuous cylindrical shape along the peripheral direction of the optical element side lens array 4E. Good.

  In the present embodiment, an example in which the protruding wall 22 is formed around the optical element side lens array 4E will be described. However, a protruding wall may naturally be formed around the fiber side lens array 4G. Even when the protruding wall is formed around the fiber side lens array 4G, the same effect as that when the protruding wall 22 is formed around the optical element side lens array 4E can be obtained. Further, when a protruding wall is formed around the fiber side lens array 4G, the spacer 12 described later is not necessary.

  The following description will be made using an optical fiber 5 as an optical transmission path for transmitting an optical signal from the lens block 4 to an external device. A flexible optical waveguide may be used instead of the optical fiber 5. A flexible optical waveguide is a flat core formed by covering a rectangular core with a clad, and is manufactured using a flexible material such as a polymer.

  A fiber side lens array 4G that protrudes forward on the fiber side is formed as an optical transmission path side lens portion at the center of the front surface 4f that is the fiber side surface of the lens block 4. The fiber-side lens array 4G condenses a plurality of optical signals emitted from the lens block 4 toward the optical fiber 5, or collimates the plurality of optical signals emitted from the optical fiber 5, respectively, into the lens block 4. A plurality of incident fiber side lenses 4g are arranged in parallel in the width direction of the lens block 4 (12 in FIG. 1B, FIG. 2 and FIG. 3). Spacers 12 are formed at the four corners of the front surface 4 f of the lens block 4. The thickness of the spacer 12 can prevent the fiber side lens array 4G from coming into contact with the end face of the optical fiber 5 accommodated in the ferrule 6. The protruding amount of each fiber side lens 4g of the fiber side lens array 4G is the same as that of a general lens array.

  Engaging holes 13 for engaging with engaging protrusions (not shown) of the ferrule 6 are formed on both sides of the fiber side lens array 4G of the lens block 4. On the contrary, the engagement protrusions may be formed on both sides of the fiber side lens array 4G of the lens block 4 and the engagement holes may be formed in the ferrule 6.

  On the back surface 4b of the lens block 4, the optical path in the lens block 4 is converted by 90 ° from the vertical direction to the horizontal direction or from the horizontal direction to the vertical direction (the optical axis of the fiber side lens array 4G is converted by 90 ° to obtain light. A reflecting surface 14 is formed as a reflecting portion (matched with the optical axis of the element side lens array 4E). For example, a mirror in which a metal thin film is deposited on the back surface 4b of the lens block 4 is used for the reflecting surface 14.

  The lens block 4 is integrally formed using optical resin or optical glass. In the present embodiment, the lens block 4 is made of an optical resin such as ultem resin, polycarbonate (PCN) resin, acrylic resin.

  As the optical fiber 5, a plurality of single-core optical fiber strands are arranged side by side in parallel, and a tape fiber (for example, an internal transmission tape fiber 5t described later in FIG. Alternatively, an internal receiving tape fiber 5r) is used.

  A plurality of fiber insertion holes 15 are formed in the ferrule 6 in the left-right direction. The ferrule 6 is used to hold and fix one optical fiber strand in each fiber insertion hole 15 in alignment with each other. In the present embodiment, an MT ferrule that constitutes a one-stage (one coupling portion with a tape fiber) MT (Mechanically Transferable) optical connector is used as the ferrule 6.

  An optical assembly 16 that converts a plurality of optical signals from the circuit board 2 into electrical signals and transmits them, or converts a plurality of optical signals from the optical fiber 5 into electrical signals and receives them, and the optical element 3 described above. The IC chip 11 and the lens block 4 are mainly configured.

  The holding substrate 7 is provided between the circuit board 2 and the lens block 4. The circuit board 2 and the holding substrate 7 are connected by providing a metal bump 17 such as an Au bump on the bottom surface of the holding substrate 7 and connecting the metal bump 17 to a pad provided on the circuit board 2 (in the case of Au bump). Is performed by Au bump connection). The circuit board 2 and the holding substrate 7 may be connected by solder bumps instead of metal bump connections.

  Optical components such as the optical element 3 and the lens block 4 are mainly mounted on the holding substrate 7. The optical element 3 and the lens block 4 are respectively mounted on different surfaces of the holding substrate 7. An IC chip 11 for driving the optical element 3 or amplifying an electric signal output from the optical element 3 is also mounted on the surface of the holding substrate 7 on which the optical element 3 is mounted. On the surface of the holding substrate 7 on which the optical element 3 is mounted, wiring for electrically connecting the optical element 3, the IC chip 11, and the electric signal circuit of the circuit board 2 is formed.

  A fitting hole 18 for fitting the projection wall 22 of the lens block 4 is formed in the holding substrate 7. The fitting hole 18 is formed at the upper part to be fitted with the fitting part 18 u into which the protruding wall 22 of the lens block 4 is fitted, and is formed at the lower part to be perpendicular to transmit an optical signal from the optical element 3 to the lens block 4. And optical path 19.

  As the holding substrate 7, a substrate made of a ceramic substrate or a silicon substrate having a linear expansion coefficient close to that of the optical element 3 or the IC chip 11 is used. In the present embodiment, a ceramic substrate is used in which it is easy to manufacture a material having a desired linear expansion coefficient and to easily form a wiring pattern and bumps.

  As shown in FIGS. 2 and 3, the optical module 1 is assembled by flip-chip mounting the optical element 3 and the IC chip 11 on the bottom surface of the holding substrate 7. Flip chip mounting is performed by providing solder bumps 20 on the upper surfaces of the optical element 3 and the IC chip 11 and connecting the solder bumps 20 to pads provided on the bottom surface of the holding substrate 7. Next, the holding substrate 7 is provided on the circuit board 2 by metal bump connection. The optical element 3 and the IC chip 11 on the bottom surface of the holding substrate 7 are disposed in the through hole 10 of the circuit substrate 2.

  Then, the projection wall 22 having the optical element side lens array 4 </ b> E formed therein is inserted into the fitting hole 18 of the holding substrate 7, so that the projection wall 22 of the lens block 4 is fitted into the fitting hole 18. As a result, the lens block 4 is positioned and fixed on the holding substrate 7 and the optical element 3 and the lens block 4 are optically coupled.

  Furthermore, when the ferrule 6 with the optical fiber 5 inserted is connected to the front surface 4f of the lens block 4, the optical coupling between the lens block 4 and the optical fiber 5 is removed, as shown in FIGS. 1 (a) and 1 (b). An optical module 1 is obtained.

  The operation of the first embodiment will be described.

  In the optical module 1, an optical element side lens array 4 </ b> E protruding to the optical element side is formed on the lens block 4, and a protruding wall 22 is formed around the optical element side lens array 4 </ b> E. A joint hole 18 is formed, the projection wall 22 is fitted into the fitting hole 18, and the lens block 4 is fixed to the holding substrate 7.

  Thereby, the lens block 4 can be easily positioned and fixed on the holding substrate 7.

  Further, since the projection wall 22 formed around the optical element side lens array 4E protects the optical element side lens array 4E, when the optical element side lens array 4E is inserted into the fitting hole 18, the optical element side lens array 4E is inserted. 4E does not hit the edge of the fitting hole 18, and therefore is not damaged, and the reliability of the lens block 4 can be improved.

  As shown in FIG. 4, the height h1 of the protruding wall 22 (the height protruding from the bottom surface 4d of the lens block 4) h1 is preferably higher than the height h2 of the optical element side lens array 4E. Thereby, the apex part of the optical element side lens array 4E can be protected, for example, in the storage state before the lens block 4 is mounted on the holding substrate 7.

  In the optical module 1, the fitting hole 18 is formed through the holding substrate 7. Thereby, the fitting hole 18 can be used as an optical path of an optical signal.

  In the optical module 1, the optical element 3 is mounted on the surface of the holding substrate 7 opposite to the lens block 4 side, and the optical element side lens array 4E of the lens block 4 and the optical element 3 are optically coupled through the fitting hole. Has been implemented.

  Thus, the optical coupling between the optical element 3 and the optical element side lens array 4E of the lens block 4 can be accurately and easily performed by the holding substrate 7.

  In the optical module 1, the optical element side lens array 4 </ b> E protruding to the optical element side of the lens block 4 is inserted into the fitting hole 18 of the holding substrate 7.

  As shown in FIG. 5, the fitting hole 18 of the holding substrate 7 has a hole diameter φn at a portion close to the optical element side lens array 4E (fitting portion 18u) and a portion farther than the optical element side lens array 4E (vertical optical path 19). It is larger than the hole diameter φf. With this structure, in the optical module 1, the protruding wall 22 formed around the optical element side lens array 4E can be fitted into the fitting portion 18u having the hole diameter φn. The optical element 3 is disposed on the holding substrate 7 at a location facing the vertical optical path 19 having the hole diameter φf. If the holding substrate penetrates with the hole diameter φn, the size of the optical element 3 is smaller than the hole diameter φn, so that it cannot be disposed on the holding substrate.

  Furthermore, in this configuration, in the configuration in which the holding substrate 7 is provided between the circuit board 2 and the lens block 4, the optical module 1 can reduce the distance between the optical element 3 and the optical element side lens array 4E. Crosstalk can be reduced.

  For example, since the distance between the lenses constituting the lens array is very narrow (for example, in a 12-channel optical module for transmission or reception, the distance between the lenses is about 250 μm), the distance between the lens array and the optical element is long. This causes crosstalk in which adjacent optical signals interfere with each other. The optical module 1 of the present embodiment can reduce the distance between the lens array and the optical element, and can reduce such crosstalk.

  In addition, by adjusting the thickness of the holding substrate 7, the distance between the optical element 3 and the optical element side lens array 4E can be set. For example, the thickness of the holding substrate 7 may be adjusted so that the distance between the optical element 3 and the optical element side lens array 4E is substantially the same as the focal length of the optical element side lens array 4E.

  As a result, the optical module 1 can suppress crosstalk in which adjacent optical signals interfere with each other even when used in an optical module that supports multi-channel, high-speed, and miniaturization.

  The optical module 1 has a circuit board 2 on which an electric signal circuit is formed on the surface opposite to the surface of the holding substrate 7 on the lens block 4 side, and is opposite to the surface of the holding substrate 7 on the lens block 4 side. A wiring for electrically connecting the optical element 3 and the electric signal circuit of the circuit board 2 is formed on this surface.

  Thus, the optical module 1 can be designed with the circuit board 2 on which the electric signal circuit is formed and the holding board 7 on which the optical element 3 and the lens block 4 are mounted as separate members. For example, the holding substrate 7 can be used by selecting a ceramic substrate in consideration of the linear expansion coefficient of the optical element 3 to be mounted. Since the ceramic substrate is a relatively expensive member, it can be reduced in size as long as the optical element 3 and the lens block 4 can be mounted. On the other hand, the circuit board 2 can be a flexible board on which an electric signal circuit is formed. In this way, the degree of freedom in designing the optical module 1 is widened, and the design becomes easy.

  Further, the holding substrate 7 is made of a ceramic substrate or a Si substrate, whereby the linear expansion coefficient of the holding substrate 7 can be close to the linear expansion coefficient of the optical element 3 or the IC chip 11 to be mounted.

  A second embodiment will be described.

  As shown in FIG. 6, in the optical module 61 according to the second embodiment, the holding substrate 7 has a single hole diameter fitting hole 68 that fits the protruding wall 62 of the lens block 64. It is formed penetrating along the thickness direction. In this structure, since the size of the optical element 3 is smaller than the hole diameter of the fitting hole 68, it cannot be disposed on the holding substrate 7.

  Therefore, the optical module 61 arranges the circuit board 2 at a position facing the fitting hole 68 (so as to cover the fitting hole 68), and sets the vertical optical path 69 on the circuit board 2 so as to face the fitting hole 68. The optical element 3 is disposed at a position facing the fitting hole 68 through the vertical optical path 69. In the optical module 61, a through hole 60 is formed so that the IC chip 11 is accommodated in the circuit board 2, and the IC chip 11 is mounted on the holding substrate 7 through the through hole 60.

  In the present embodiment, the height of the projecting wall 62 is made equal to the thickness of the holding substrate 7 in order to fix the lens block 64 to the holding substrate 7 more stably. Further, in order to minimize the distance between the optical element 3 and the optical element side lens array 64E, the optical element side lens array 64E of the lens block 64 is lighter than the optical element side lens array 4E of the optical module 1 described in FIG. It protruded to the element 3 side.

  In the optical module 61, the distance between the optical element 3 and the optical element side lens array 64E is larger than the distance between the optical element 3 of the optical module 1 and the optical element side lens array 4E. Since 68 may be penetrated with a single hole diameter, the structure can be simplified.

  The optical module 1 described above is particularly useful when used, for example, as a mounting structure of the main part of the optical module 71 as shown in FIG.

  As shown in FIG. 7, an optical module (optical transceiver) 71 is a pluggable multi-channel optical module that is detachably provided in a host device (external device) such as a network device such as a switching hub or a media converter. FIG. 7 illustrates an example in which a total of 2 × 12 channels, that is, a 24 channel type and 3 Gbps signals per channel are transmitted by transmission and reception.

  This optical module 71 converts a plurality of electrical signals from the host device into optical signals and transmits them to the external transmission line via the internal transmission optical fiber 5t, while the internal reception optical fiber 5r is transmitted from the external transmission line. A plurality of optical signals are received via the digital signal and converted into an electrical signal and transmitted to the host device.

  The optical module 71 includes an optical transmission assembly 16t mounted on the holding substrate 7 mounted on the circuit board 2, and an optical reception assembly 16r.

  At the other end of the circuit board 2 on the upper device side, a card edge portion 9 configured by forming a plurality of connection terminals 8 for connecting to the upper device in parallel in the substrate width direction is provided. By inserting the card edge portion 9 into a card edge connector provided in the host device, the hot insertion / extraction of the optical module 71 can be performed.

  The optical transmission assembly 16t uses the transmission optical element array as the optical element 3 in the optical assembly 16 described with reference to FIGS. 1 and 2, and the driver IC that drives and modulates the transmission optical element array as the IC chip 11. Is. The optical receiving assembly 16r uses a receiving optical element array as the optical element 3 in the optical assembly 16, and a preamplifier IC that amplifies an electric signal output from the receiving optical element array as the IC chip 11.

  On the fiber side of the circuit board 2, a male two-stage MPO (multi-core collective connection using MT ferrule) optical connector 72 is provided as an optical connector connected to an external transmission path. The male two-stage MPO optical connector 72 is held and fixed to the module case.

  The male two-stage MPO optical connector 72 includes a two-stage MT optical connector 73 in which one end of the internal transmission optical fiber 5t is connected to the upper stage, and one end of the internal reception optical fiber 5r is connected to the lower stage. It consists of a claw member (receptacle part) 74 that is attached to the stage MT optical connector 73 and engages with a female two-stage MPO optical connector as an external optical connector.

  This claw member 74 and the concave portion of the female two-stage MPO optical connector constitute a latch mechanism. The female two-stage MPO optical connector is connected with a transmission / reception optical fiber as an external transmission path. An optical cable may be used as the transmission / reception optical fiber, or a tape fiber may be used as a relay transmission path in the preceding stage.

  In the optical module 71 of FIG. 7, the optical transmission assembly 16t is mounted on the upper device side of the circuit board 2 and the optical reception assembly 16r is mounted on the fiber side of the circuit board 2 in order to prevent deterioration of the electrical signal for transmission. Although an example has been shown, when the transmission speed is about 1 Gbps, or when deterioration of the electrical signal for transmission is not affected, the mounting positions of the optical transmission assembly 16t and the optical reception assembly 16r may be reversed.

  Further, the optical module 71 in FIG. 7 may include a case that accommodates the circuit board 2, the lens block 4, and the ferrule 6 and that fits the optical connector 72 and holds it. In FIG. 7, an upper and lower case composed of an upper case 75 u and a lower case 75 d is shown.

  In the embodiment described above, the projection wall 22 and the projection wall 62 are formed only around the optical element side lens array 4E and 64E. In addition, the same projection wall is formed around the fiber side lens array 4G. Or a similar protruding wall may be formed only around the fiber side lens array 4G.

FIG. 1A is a longitudinal sectional view of an optical module using a lens block showing a preferred first embodiment of the present invention, and FIG. 1B is a perspective view thereof. It is the disassembled perspective view which decomposed | disassembled the lens block from FIG.1 (b) and was seen from the bottom face side. It is the disassembled perspective view which decomposed | disassembled the lens block from FIG.1 (b). It is an expansion perspective view of an optical element side lens part. It is an enlarged vertical sectional view of the periphery of the optical element side lens part. It is a longitudinal cross-sectional view of the optical module using the lens block which shows the 2nd Embodiment of this invention. It is a perspective view which shows a more detailed example of an optical module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical module 2 Circuit board 3 Optical element 4 Lens block 4E Optical element side lens array (Optical element side lens part)
4G fiber side lens array (optical transmission path side lens part)
5 Optical fiber (external optical transmission line)
6 Ferrule 7 Holding substrate 14 Reflecting surface (reflecting part)
22 Projection wall

Claims (5)

  The optical transmission path side lens unit optically connected to the external optical transmission path, the optical element side lens unit optically connected to the optical element, and the optical axis of the optical transmission path side lens unit are converted by 90 °. A lens block comprising a reflecting portion that matches the optical axis of the optical element side lens portion, wherein a projection wall is formed around the optical element side lens portion and / or the optical transmission path side lens portion. block. A lens block according to claim 1;
A first substrate on which a fitting hole for fitting with the protruding wall of the lens block is formed;
An optical module comprising a second substrate on which an electric signal circuit is formed,
The optical element and the electronic element are disposed on the first substrate, and a through-hole for exposing the optical element and the electronic element disposed on the first substrate is formed on the second substrate. And the second substrate is disposed on a surface opposite to the surface of the first substrate on which the lens block is mounted.   The fitting hole of the first substrate is a portion where the hole diameter of the portion near the optical element side lens portion and / or the optical transmission path side lens portion is farther than the optical element side lens portion and / or the optical transmission path side lens portion. The optical module according to claim 2, wherein the optical module is larger than the diameter of the hole. A lens block according to claim 1;
A first substrate on which a fitting hole for fitting with the protruding wall of the lens block is formed;
An optical module comprising a second substrate on which an electric signal circuit is formed,
An electronic element is disposed on the first substrate, a through hole is formed in the second substrate for exposing the electronic element disposed on the first substrate, and the lens block is mounted. The second substrate is disposed on a surface opposite to the surface of the first substrate.
The fitting hole of the first substrate has a single hole diameter, the second substrate is disposed at a position facing the fitting hole, and at a position facing the fitting hole of the second substrate. An optical module comprising the optical element.   The optical module according to claim 2, wherein the first substrate is made of a ceramic substrate or a Si substrate.

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