JPH10123372A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily and hermetically seal wiring materials, lead terminals, etc., by supporting the optical element mounting side of a first substrate on a second substrate and tightly covering the surface of this second substrate with a covering material including its optical transmission lines and optical elements. SOLUTION: The optical element 35, 36 side of the first substrate is entirely integrated and covered including the bonding wires by the second substrate 41 and covering material 61 adjusted to have the equal coefft. of linear expansion. The influence that external light intrudes to the parts of the optical elements 35, 36 is, therefore, eliminated and the entire part expands and shrinks cooperatively with respect to a temp. change, thereby obviating the occurrence of such inconvenience that the peeling occurs at the boundary with, for example, the first substrate 31 based on the internal stress fluctuation and expansion and contraction. If the element is a light emitting element (LD chip) 35, the heat generated according to the operation is transmitted to the element placing plate 47. The heat is transmitted to a suitable external heat transmission means or heat radiating means through the lead terminals connected to the placing plate 47, by which the temp. rise of the element may be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical module including an optical element and an optical transmission line. In optical communication or the like, a terminal portion of an optical fiber which is a transmission line of an optical signal requires a circuit for converting an electric signal into an optical signal or converting an optical signal into an electric signal. A light emitting element or a light receiving element is used for such signal conversion, and these optical elements are optically connected to an optical transmission line and are hermetically sealed.

[0002]

2. Description of the Related Art As shown in the side sectional view of FIG. 26, a conventional optical module is composed of a lead terminal 2 which penetrates a bottom surface of a container 1 made of metal or ceramic such as Kovar or the like, and glass or sapphire on the side surface. A transparent window 3 such as is provided in an airtight manner, and an optical element 5, such as an LD (laser diode) or a PD (photodiode), a collimating lens 6, and the like are adjusted and disposed inside, and the outside of the window 3 is fixed. After the optical fiber 8 supported by the optical fiber support 7 is aligned in the X, Y, and Z directions, the optical fiber support 7 is fixed to the container 1 by laser welding or the like.

The interior of the container 1 is filled with an inert gas,
Is welded over the entire circumference to seal the inside of the container 1 and shield it from the outside air. Reference numeral 11 denotes a bonding wire for electrical connection.

[0004]

In the above-mentioned conventional optical module, the position of the optical element 5, the lens 6, etc. is adjusted and fixed inside the container 1, and the airtight window 3, the airtight lead terminal 2, and the like are provided. In addition, the lid 9 must be hermetically sealed, and the optical fiber 8 needs to be positioned and welded and fixed. It required a jig, a supporting device, etc., and had gone through complicated processes.

[0005] With the above configuration, it is difficult to reduce the size of the optical module itself, and it has not been possible to reduce the size to some extent. In view of such a conventional technology, the present invention has been made to realize an optical module that can be simplified and reduced in size.
An optical module as shown in a perspective view in FIG.

That is, an optical transmission line 14, which is a double-embedded optical waveguide, is formed on a silicon substrate 12 by reacting and reacting a glass starting material and controlling the refractive index while vitrifying. A light-emitting element (LD chip) 15 and a light-receiving element (PD chip) 16 are directly opposed to one end face of the optical transmission path 14 at one end on the substrate 12 so as to be optically coupled. A coating layer 17 made of a synthetic resin such as an epoxy resin, which is mounted and hermetically covers the substrate 12 including the optical element, is formed.

With this configuration, an optical module for optical transmission and reception that can be simplified and extremely miniaturized has been made possible. With the optical waveguide 14 as a single line, it is of course possible to provide a light transmitting module equipped with only a light emitting element or a light receiving module equipped with only a light receiving element.

On the substrate 12 near the optical elements 15 and 16,
A bonding pad 19 for relay is formed, and a plurality of bonding pads 21 for connecting to an external circuit or a peripheral circuit are formed on a rear end surface of the substrate 12.
The relay bonding pad 19 and the optical elements 15 and 16 are connected by a bonding wire 22, and the gap between the relay bonding pad 19 and the bonding pad 21 is
The connection formed on the substrate 12 is connected by a conductor pattern, and the bonding pad 21 is connected to an external circuit by a bonding wire 23 in a predetermined relationship.

Further, a circuit pattern is formed on the substrate 12 around the optical elements 15 and 16, and a circuit element chip such as an IC and a circuit element such as a capacitor and a resistor are mounted on the substrate 12. It is also possible to cover.

The substrate 12 is mounted and fixed on a mounting substrate 24, and another optical waveguide, for example, an end face of an optical fiber is connected to the optical waveguide 14 exposed at the front end face.

Here, when a predetermined temperature cycle test and a humidity test were performed to confirm long-term reliability, as shown in the side view of FIG. The expansion and contraction force as shown by the arrow is based on the difference in the linear expansion coefficient between the substrate 12 and the coating layer 17.
, And as shown in FIG.
A situation such as separation 25 occurred above.

As another problem, shrinkage occurs during the process of curing the synthetic resin as the coating layer 17, and this shrinkage may cause cracks in the coating layer 17, and in an extreme case, the substrate 12 In some cases, damage may occur.

Extending the coating layer 17 as shown by a two-dot chain line in FIG. 2B by providing an optical switch or the like (not shown) on the optical waveguide 14 causes the above-described problem more easily. It will be.

In order to make the coefficient of linear expansion of the coating layer 17 coincide with or approximate the coefficient of linear expansion of the substrate 12, it is conceivable to mix a short fiber of glass (filler) or the like in a synthetic resin. However, there are also problems that the bonding wire 23 cannot be completely covered and protected, and that the problem of peeling cannot be reliably eliminated.

If an opaque synthetic resin is applied to the coating layer 17, the synthetic resin flows into the optical coupling portion with the optical elements 15 and 16, which causes inconvenience. Therefore, it is necessary to take special measures to prevent the synthetic resin from flowing. It turned out that it was.

From the above, if a transparent synthetic resin is used so that the coating layer 17 does not affect the optical coupling between the optical elements 15 and 16 and the optical waveguide 14, external light may enter and cause another influence. Was also found to occur.

In view of the various problems described above, an object of the present invention is to solve these problems and to provide an optical module which is reduced in size and improved in long-term reliability. It is.

[0018]

Means for Solving the Problems According to the gist of the present invention for achieving the above object, a first means comprises an optical transmission line and an optical element optically coupled to one end of the optical transmission line. A first substrate comprising a first substrate and a second substrate made of a synthetic resin having a plurality of lead terminals and supporting the optical element side together with the optical transmission path with the other end of the optical transmission path as the outside,
An optical module in which the second substrate is integrally covered with the second substrate in cooperation with the second substrate by a covering material made of a synthetic resin, including the optical transmission path of the first substrate and the optical element. .

According to the first means, basically, the first
This is simple because the optical element that is optically coupled to the end of the optical transmission path is mounted on the substrate. In a state where the optical element mounting side of the first substrate is supported on the second substrate, the second substrate is densely covered with a covering material including the optical transmission path and the optical element to be integrated.

Preferably, the synthetic resin material of the second substrate and the synthetic resin material of the coating material cooperate with the first substrate material so that the coefficient of linear expansion matches or approximates the optical transmission coefficient. Since the path and the optical element are densely covered in an enclosing state, the expansion and contraction due to the temperature change are not affected since the whole expands and contracts in unison.

The second means includes a first substrate having an optical transmission line and an optical element optically coupled to one end of the optical transmission line, a plurality of lead terminals, and the other end of the optical transmission line. A second substrate made of a synthetic resin that supports the optical element side together with the optical transmission path as an exterior, and a wall mounted on the second substrate across the first substrate at the other end of the optical transmission path The second substrate is integrally covered with the second substrate in cooperation with the second substrate by a covering material made of a synthetic resin including the optical transmission path of the first substrate and the optical element. Optical module.

According to the second means, basically, the first
This is simple because the optical element that is optically coupled to the end of the optical transmission path is mounted on the substrate. In a state where the optical element side of the first substrate is supported on the second substrate, a wall is placed on the second substrate across the first substrate at the other end of the optical transmission path, The second substrate is densely covered with a covering material including the optical transmission path and the optical element, and integrated.

Preferably, the synthetic resin material of the second substrate and the synthetic resin material of the covering material cooperate with the first substrate material so that the coefficient of linear expansion coincides with or approximates that of the first substrate material. Since the path and the optical element are densely covered in an enclosing state, the expansion and contraction due to the temperature change are not affected since the whole expands and contracts in unison.

By disposing the wall, the coated coating material shrinks as it cures, but by moving the adhered wall in the shrinking direction, the coating material cracks due to shrinkage. Is prevented.

The third means has a first substrate having an optical transmission line composed of laminated optical waveguides, an optical element optically coupled to one end of the optical transmission line, and a plurality of lead terminals. A second substrate made of a synthetic resin that supports the optical element side together with the optical transmission path with the other end of the optical transmission path as the outside, and an optical transmission path of the first substrate on the second substrate. An optical module comprising: a cover made of a synthetic resin including a substrate and an optical element;

According to the third means, the optical transmission line is a buried-type optical transmission line in which the optical waveguide is directly formed on the first substrate. Since the optical transmission line is integrated with the substrate, the manufacturability and the positional accuracy are good. .

Basically, the configuration is simple because an optical element optically coupled to the end of the optical transmission line is mounted on the first substrate. In a state where the optical element mounting side of the first substrate is supported on the second substrate, the second substrate is densely covered with a covering material including the optical transmission path and the optical element to be integrated.

Preferably, the synthetic resin material of the second substrate and the synthetic resin material of the covering material cooperate with the first substrate material so that the coefficient of linear expansion coincides with or approximates that of the first substrate material. Since the path and the optical element are densely covered in an enclosing state, the expansion and contraction due to the temperature change are not affected since the whole expands and contracts in unison.

The fourth means comprises a first substrate having an optical transmission line composed of an optical fiber, an optical element optically coupled to one end of the optical transmission line, and a plurality of lead terminals. A second substrate made of a synthetic resin supporting the optical element side together with the optical transmission path with the other end of the optical element as an external part, and the optical transmission path of the first substrate and the optical element on the second substrate. And an optical module that is tightly covered and integrated with a second substrate in cooperation with a covering material made of a synthetic resin.

According to the fourth means, since the known optical fiber is arranged and fixed on the first substrate, stable optical transmission can be performed. Basically, the optical transmission is performed on the first substrate. The configuration is simple because an optical element that is optically coupled to the end of the road is mounted. The optical element side of the first substrate is
While being supported on the substrate, the second substrate is densely covered with a covering material including the optical transmission line and the optical element, and integrated.

Since the optical transmission line of the first substrate is an optical fiber, it is advantageous that the optical coupling with an optical fiber as an external optical transmission line be matched. Preferably, the synthetic resin material of the second substrate and the synthetic resin material of the coating material have a coefficient of linear expansion that matches or approximates that of the first substrate,
Since the optical transmission path and the optical element are tightly covered in an encircling state in cooperation with each other, the expansion and contraction due to the temperature change are not affected because the entire expansion and contraction occur in unison.

The fifth means comprises a plurality of lead terminals, a substrate mounting plate extending from the lead terminals, an optical transmission path, and an optical element optically coupled to one end of the optical transmission path. And a substrate mounted on a plate, and the other end of the optical transmission path is external and the optical transmission path on the optical element side of the substrate and the optical element are densely covered with synthetic resin and integrated. Module.

According to the fifth means, the substrate is mounted and positioned on the substrate mounting plate extending from the lead terminal, and the optical fiber transmission path on the optical element side of the substrate mounting plate and the substrate and the synthetic resin including the optical element are included. Since it is densely covered by the mold, the moldability is good, and it can be formed in a short time.

Preferably, when the synthetic resin is made to match or approximate the linear expansion coefficient of the substrate, the expansion and contraction due to the temperature change is not affected because the whole expands and contracts. The sixth means includes an optical transmission path on the substrate and an optical element optically coupled to one end of the optical transmission path, and is densely covered with a synthetic resin and integrated, and an optical transmission path is provided at the other end of the optical transmission path. An optical module in which fibers are connected and housed in a synthetic resin case, and the optical fibers are led out of the case.

According to the sixth means, the optical transmission line is optically coupled to one end of the optical transmission line on the substrate, and the optical element is densely covered with a synthetic resin and integrated, and the optical fiber is connected to the substrate at the other end side of the optical transmission line. Are connected and accommodated in a case, and this optical fiber is led out of the case, thereby achieving a small size and good reliability.

By making the synthetic resin match or approximate to the coefficient of linear expansion of the substrate, the expansion and contraction due to the temperature change are matched and expanded as a whole, so that there is no influence.

[0037]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an optical module according to an embodiment of the present invention; Note that the same reference numerals are given to the same parts throughout the drawings for easy understanding.

FIG. 1 is an external view of a first substrate according to the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a side view, and FIG. 1 (c) is a perspective view. In the figure, the first substrate 31
Is known. A vitrified material is laminated and deposited on a silicon substrate 32 while reacting a glass starting material, and an optical transmission line 33, which is a two-embedded optical waveguide, is formed by vitrification to control the refractive index. A light emitting element (LD chip) 35 is formed on one end of the substrate 32 by a technique.
And a light receiving element (PD chip) 36 are mounted so as to directly oppose each optical transmission path 33 so as to be optically coupled.

Specifically, LD is disclosed in Japanese Patent Application No. 06-1651.
No.45 LD with tapered waveguide, PD is patent application No. 0
No. 7-114629 discloses a chamfer-incidence type PD, in which high-efficiency and simple mounting is performed by passive alignment using image recognition. The gap between the waveguide and the LD or the PD is set to 20 to 30 μm.

On the substrate 32 near the optical elements 35 and 36,
A bonding pad 37 for relay is formed, and a plurality of bonding pads 38 for connecting to an external circuit or a peripheral circuit are formed at the rear end of the substrate 32.
The relay bonding pad 37 and the optical elements 35 and 36 are connected by bonding wires 39, and the relay bonding pad 37, the optical elements 35 and 36, and the bonding pad 38 for connecting an external circuit are formed on a substrate (not shown). Respectively.

FIG. 2 shows an external view of the second substrate 41 and a cross-sectional view of a main part. That is, FIG. (A) is a plan view, FIG. (B) is a front view, FIG. (C) is a front cross-sectional view, FIG. (D) is a side view, and FIG. (E) is a side cross-sectional view.

The box-shaped substrate 42 is a molded product of a synthetic resin, and has an opening 43 on the front wall surface and a groove 45 on the bottom surface continuing from the opening. Two independent lead terminals 46 and two lead terminals 48 connected to the substrate mounting plate 47 exposed to the concave groove portion 45 are led out to the front side surface. 5 on the other side
Two independent lead terminals 49 are respectively derived. The independent lead terminals 46 and 49 are exposed inside the bottom surface of the substrate 42.

These lead terminals 46, 48 and 49 are all formed by a frame portion made of a conductive metal (not shown).
The outer end is integrally formed by coupling. The frame is cut and removed after being molded on the box-shaped substrate 42, and is shown in the drawing.

The box-shaped substrate 42 is formed in a synthetic resin material so as to have the same or approximate linear expansion coefficient as that of the first substrate 31.
Short fibers (fillers) such as glass and carbon are mixed to control the expansion coefficient.

FIGS. 3 and 4 show a state in which the first substrate 31 and the second substrate 41 are combined. That is, FIG. 3 is a perspective view of the separated state, FIG. 4A is a plan view of the combined state in FIG. 4A, FIG. 4B is a front view in FIG. 4B, and FIG.

From the upper side of the second substrate 41, the first substrate 31
Are aligned in the illustrated direction and placed in the concave groove portion 45, the tip of the optical waveguide 33 of the first substrate 31
From the opening portion 43 of the substrate 41. Positioning is performed by matching the rear end surface of the first substrate 31 to the end of the groove portion 43. At the time of mounting, the epoxy resin adhesive is supplied thinly and densely into the concave groove portion 45, and the first substrate 31 is securely bonded and fixed.

In this state, the bonding pads 38 for connecting the external circuit of the first substrate 31 and the insides of the lead terminals 46 and 49 of the second substrate 41 are connected to the bonding wires 51.
Are connected in a predetermined manner.

Next, a wall 55 made of a synthetic resin plate is arranged in contact with the inside of the second substrate 41 on the side of the opening 43. The height of the wall 55 is equal to the height from the bottom surface to the top surface of the box-shaped substrate 42, and the lower central portion is cut out so as to straddle the first substrate 31 as well shown in FIG. 56 are formed. FIG. 4 shows a state assembled as described above.

Referring to the sectional side view of FIG. 5, as shown in FIG. 5A, the optical elements 35 and 3 on the first substrate 31 are formed.
The optically transparent synthetic resin 58, for example, a silicone resin or an epoxy-based resin, is supplied to cover the area including the vicinity of the bonding pad 6 and the relay bonding pad 37 and on the waveguide 33.

The step of supplying the optically transparent synthetic resin 58 may be at the time shown in FIG. 1 or at an appropriate time thereafter. After the curing of the transparent synthetic resin 58, the first substrate 3 is placed inside the box-shaped substrate 42 of the second substrate 41 as shown in FIG.
A covering material 61, for example, an epoxy-based resin is injected so as to cover one portion, and cured by heating to form a covering layer.

The coating material 61 is mixed with short fibers (fillers) such as glass and carbon for controlling the coefficient of linear expansion after curing, and the coefficient of linear expansion matches the box-shaped substrate 42. In the process of curing the coating material 61 and lowering it to room temperature, the adhered wall 55 is drawn in the shrinking direction as it shrinks.

The fact that such a wall 55 is disposed means that if the wall 55 is not disposed, the covering material 61 adheres to the inner surface of the side wall of the box-shaped substrate 42 on the side of the opening 43 and becomes unspecified with shrinkage. There is a possibility that a crack (crack) may occur at an intermediate position, and this is an effective measure that can surely eliminate the occurrence of such an inconvenient situation by drawing and moving the wall 55.

It is preferable to remove air or the like contained in the coating material 61 under reduced pressure or in a vacuum atmosphere prior to injection, and to prevent air from being taken in during injection. It is preferably carried out in

The optical module 65 of the present invention can be appropriately used in the state shown in FIG. That is, by covering the periphery including the optical elements 35 and 36 on the first substrate 31 with the optically transparent synthetic resin 58, the optical elements 35 and 36 and the waveguide 33 is optically coupled.

Since the second substrate 41 and the coating material 61 having the same linear expansion coefficients integrally cover the optical elements 35 and 36 of the first substrate including the bonding wires, the first substrate is covered with light. In addition to eliminating the effect of external light entering the elements 35 and 36 and expanding and contracting as a whole in response to temperature changes, the first and second elements are based on internal stress fluctuations and differences in expansion and contraction. Inconvenience such as peeling at the boundary surface with the substrate 31 does not occur.

When the element is a light emitting element (LD chip) 35, the heat generated during the operation is transmitted to the substrate mounting plate 47, and an appropriate external heat transfer means is provided through a lead terminal 48 continuous with the substrate mounting plate 47. By transmitting heat to the heat radiating means, it is possible to suppress an increase in the temperature of the element.

A more preferred embodiment of the present invention will be described with reference to FIGS. 6A is a plan view, FIG. 6B is a side view, FIG. 6C is a front view, and FIG. 6D is a bottom view.

FIG. 6 shows a second embodiment of the optical module according to the present invention. The basic configuration is the same as that shown in FIG. 5B, and the lead terminals 46, 48 and 49 are provided. The box-shaped substrate 42 is bent in the lower surface direction on the side surface so as to be parallel to each other. By processing in this manner, mounting can be performed by penetrating through holes in a printed wiring board or the like.

As shown in FIG. 6D, a substrate mounting plate 47 is provided on the bottom of the box-shaped substrate 42 of the optical module 66.
Are provided at two locations.
FIG. 7 shows a housing case 71 for further developing the optical module of the present invention. (A) is a plan view, (b) is a front view, (c) is a side sectional view, and (d) is a side view.

An optical module housing 72 shown on the right side of FIGS. 7A and 7C, and a housing 73 for the optical coupling unit are formed on the left side, and the linear expansion coefficient is not particularly controlled. Is a phenolic resin, an epoxy resin, a PPS (polyphenylene sulfide) resin, or a synthetic resin molded product such as a PC (polycarbonate) or an ABS resin to which a filler for reinforcement or the like is added or not. It consists of

The optical module accommodating portion 72 is provided with terminal row through-holes 75 parallel to both sides, and positioning columnar projections 76 at two locations in the front-rear direction at the center of the bottom surface. The partition wall 77 between the optical module housing portion 72 and the housing portion 73 of the optical coupling portion has a notch 7 for communicating both sides at the center.
8 are formed.

Notches 79 for holding optical fiber holding bushes at two places are provided on the front wall of the housing 73 of the optical coupling section.
79 are formed. The periphery of the bottom surface is protruding, and a step surface 81 and hooks 82 for engaging the lid on the outer side surfaces of both walls are formed with two inclined surfaces each having an inclined surface for sliding. I have.

FIG. 8 shows the first stage of the optical module assembly procedure. Figure (a) is a plan view, Figure (b) is a front view,
Figure (c) is a side sectional view. First, the optical module 66 shown in FIG. 6 is arranged and placed on the optical module accommodating portion 72 of the accommodating case 71, and an epoxy-based adhesive is provided between the optical module 66 and the bottom surface of the second substrate 41. An adhesive or the like is applied and supplied, and the columnar projections 76 and the holes 67 are aligned, fitted and positioned, and the adhesive is cured to fix them.

The lead terminals 46 and 4 of the optical module 66
8 and 49 pass through the terminal row through-hole 75 and protrude downward, and the front end side of the first substrate 31 is located in the receiving portion 73 of the optical coupling portion via the notch 78.

FIG. 9 shows another first stage of the optical module assembly procedure. As in FIG. 8, FIG. 9A is a plan view, FIG. 9B is a front view, and FIG. FIG. 7 is a cross-sectional view showing a cutout 7 for holding an optical fiber supporting bush on a front wall of a housing 73 of an optical coupling unit of a housing case 71-1.
9 is only one place.

In the optical module 66-1, only the light emitting element (LD chip) 35 or the light receiving element (PD chip)
Only one optical waveguide 33 is used as the optical waveguide 33 in the first substrate 31-1.

FIG. 10 shows an additional means 83 for optically connecting an optical fiber, which is an optical waveguide at the tip of the first substrate 31 of the optical module 66. Figure (a)
Is a front view, FIG. (B) is a side view, and FIG. (C) is a front view.

The adding means 83 is made of, for example, U-shaped transparent glass, and is attached to the front end portion of the first substrate 31 so as to straddle from above. This is because the narrow end surface of the first substrate 31 is substantially increased in the front view, the upper side, and the left and right direction, and the end surface is a flat polished surface, which is exactly coincident with the end surface of the first substrate 31. .

For mounting, for example, an ultraviolet-curing UV adhesive is applied to the contact surfaces where they are fitted to each other, fitted together, and irradiated with ultraviolet rays for curing and bonding. The attaching step of the adding means 83 may be in the state shown in FIG. 1 or FIG. 6 or may be in the state shown in FIG. 8 or FIG. Can be done.

FIG. 11 is a plan view of a connection end of an optical fiber for connecting the optical module of the present invention to an external optical transmission line. In FIG. 7A, the coating is removed from the ends of the two single-core optical fibers 85, and the optical fiber core 86 is led out. As shown in the end view of FIG. 9B, for example, it is sandwiched and fixed between two holders 87 and 88 made of transparent glass.

As shown in the enlarged end view of FIG. 12A, the holders 87 and 88 have an accurate V such that the optical fiber core 86 just fits on each of the opposing surfaces.
The grooves 91 and 92 are formed in parallel, and the optical fiber core 86 is sandwiched and fixed as shown in the combined state diagram of FIG.

The center distance between the adjacent optical fiber cores 86, 86 is set to exactly match the center distance between the optical waveguides 33, 33 of the first substrate 31 shown in FIG.

The end surfaces of the holders 87 and 88 are flat polished surfaces, and the size of the combined area includes the additional means 83 fixed to the end surface of the first substrate 31 shown in FIG. It is equal to the size of the area of the end face.

With the end faces of the holders 87 and 88 and the end faces of the optical fiber core wires 86 exactly coincident with each other, for example, a UV adhesive is applied and supplied to the combined faces, and ultraviolet rays are irradiated to cure the combined faces.

A rubber holding bush 93 is fitted around each end of the covering portion of the optical fiber 85. In the holding bush 93, the direction in which the optical fiber 85 extends is a tapered cylindrical shape, and is integrally formed with two flange-shaped portions 94 at an end portion thereof and a fitting portion 95 having a rectangular cross section between them. A suitable rubber adhesive is applied between the holding bush 93 and the coated surface of the optical fiber 85,
Glued so that it does not move or fall out easily.

The fitting portion 95 of the holding bush 93 of the optical fiber assembly assembled as shown in FIG.
13 is inserted into the notch 79 of the storage case 71 in FIG. 8 and inserted into the notch 79, as shown in the plan view of FIG.
In this state, the end faces of the holders 87 and 88 holding the distal end of the optical fiber core 86, the end face of the first substrate 31 and the end face of the adding means 83 are combined with the optical waveguide 33 and the optical fiber core 86. Jig for positioning,
Positioning is performed while checking with a measuring device or the like, and a light adhesive between the end faces, for example, a UV adhesive is supplied, and ultraviolet rays are irradiated to cure and bond.

In the optical fiber 85, the holding bush 93 is fitted into the notch 79 of the housing case 71,
4 and the fitting portion 95 is not rotated since it is rectangular, so that a stable state is maintained.

The length and shape of the optical fiber core 86 are preset in the state of FIG. 11 so as to obtain a reasonable illustrated state, so that the assembly can be performed smoothly. Since the assembly is completed as described above, FIG.
As shown in the side sectional view of FIG.
A cover 97 is put on the upper opening side of the device 1 and pushed in. Although not shown on both sides of the lid 97, a square hole is provided which just engages with the hook 82 on the side of the storage case 71,
This square hole engages with the hook 82 and does not come off as it is.

Referring to FIG. 14, a jack-type optical connector 98 is attached to the tip of each of the optical fibers 85 to connect to an optical transmission line for optical transmission and an optical transmission line for optical reception, respectively. Optical module 1
01 is indicated.

Referring to FIG. 15, the optical fiber 85
A jack-type optical connector 98 is attached to the tip of the optical transmission module. When only a single light emitting element (LD chip) 35 is provided as an optical element, only the light transmitting module and the light receiving element (PD chip) 36 are provided. In the case where the optical module 102 is provided, the optional optical module 102 as the optical receiving module is shown. In this embodiment, the storage case 71-1
The cover 97-1 has a cutout 79 for the optical fiber 65 at one place.

FIG. 16 shows a fifth embodiment of the optical module according to the present invention. The basic configuration is the same as that shown in FIGS. 3, 4, and 5, except that the wall 55-1 covers the first substrate 31 as shown in the perspective view of FIG. As described above, the protruding portion 105 extending in the directions of the optical elements 35 and 36 is provided. Therefore, the notch 56 that straddles the first substrate 31 also extends to the protrusion 105.

In FIG. 13B, the other parts are denoted by the same reference numerals, and detailed description of the configuration is omitted. Therefore, the above description should be referred to with the drawings as necessary. As shown in FIG. 2B, the opening 4 of the second substrate 41 is formed.
A wall 55-1 made of a synthetic resin is arranged in contact with the inside on the third side. The height of the wall is equal to the height from the bottom surface to the upper surface of the second box-shaped substrate 42, and the notch 56 formed including the protrusion 105 on the lower side is fitted to the first substrate 31.

An optically transparent synthetic resin 58 is supplied to cover the first substrate 31, including the vicinity of the optical elements 35, 36 and the relay bonding pad 37 and on the waveguide 33. After curing, the first substrate 31 and the projection 10 are provided inside the box-shaped substrate 42 of the second substrate 41.
5, a coating material 61, for example, an epoxy-based resin is injected and cured by heating to form a coating layer.

The coating material 61 is mixed with short fibers (fillers) such as glass and carbon for controlling the linear expansion coefficient after curing, and the linear expansion coefficient matches that of the box-shaped substrate 42. In the process of curing the coating material 61 and lowering it to room temperature, the adhered wall body 55-1 is drawn in the shrinking direction as it shrinks.

The disposition of the wall member 55-1 means that if the wall member 55-1 is not disposed, the covering material 61 adheres to the side wall surface of the box-shaped substrate 42 on the side of the opening 43, and the shrinkage occurs. There is a possibility that a crack (crack) may occur at an unspecified intermediate position, and the occurrence of such an inconvenient situation can be surely eliminated by drawing and moving the wall body 55-1.

The projection 105 of the wall 55-1 covers the first substrate 31, but by doing so, the first
Since the bonding surface between the substrate 31 and the coating layer made of the coating material 61 is reduced, the internal stress generated by the expansion and contraction action at this interface is reduced due to the change in the ambient temperature accompanying the operation of the optical module 65-1. It will be greatly eased.

Since the second substrate 41 and the covering material 61 whose linear expansion coefficients are adjusted are all integrally covered with the first substrate 31 including the bonding wires on the optical element 35 and 36 sides, The influence of external light from entering the portions of the optical elements 35 and 36 is eliminated, and the entire device cooperates and expands and contracts in response to a temperature change. For example, inconvenience such as peeling off at the boundary surface of the first substrate 31 does not occur.

FIG. 17 shows a sixth embodiment of the optical module of the present invention. The basic configuration is the same as in FIGS. 3, 4, and 5, except for the inner wall surface of the second substrate 41 on the side of the opening 43, as shown in the plan view of FIG. And the wall surface 55-2 is formed by coating and filling so as to cover the opening 43.

The wall surface 55-2 is hard to adhere to the coating material 61, and is made of, for example, a silicone resin or tetrafluoroethylene resin (Teflon). However, it is assumed that the surface side of the second substrate 41 is subjected to a base treatment such as activation so as to be surely adhered.

In FIG. 4A, the related parts such as the bonding wires 51 as shown in FIG. 4 are not shown because they are complicated. Parts other than the wall surface 55-2 are denoted by the same reference numerals, and detailed description thereof will be omitted. Therefore, the above description should be referred to with the drawings as necessary.

As shown in FIG. (B), the first substrate 3
The opening 43 is closed by a wall surface 55-2 covering the upper part 1. The height of the wall surface 55-2 is from the bottom surface to the upper surface of the box-shaped substrate 42.

An optically transparent synthetic resin 58 is supplied to cover the first substrate 31, including the optical elements 35 and 36, the vicinity of the relay bonding pad 37 (not shown), and the waveguide 33, and After the synthetic resin 58 is cured, a coating material 61, for example, an epoxy resin is injected into the inside of the second substrate 41 on the box-shaped substrate 42 so as to cover the first substrate 31, and is heated and cured. Form a coating layer.

The coating material 61 is mixed with short fibers (fillers) such as glass and carbon for controlling the linear expansion coefficient after curing, and the linear expansion coefficient matches that of the box-shaped substrate 42. In the process of curing the coating material 61 and dropping it to room temperature, the shrinkage causes the coating material 61 to separate from the wall surface 55-2 and shrink independently because it adheres to the wall surface 55-2 and is not adhered.

The formation of such a wall surface 55-2 means that if the wall surface 55-2 is not formed, the covering material 61 adheres to the side wall surface of the box-shaped substrate 42 on the side of the opening 43, and becomes inconsistent with shrinkage. Cracks (cracks) may occur at specific intermediate positions, and by separating from the wall surface 55-2, occurrence of such an inconvenient situation can be reliably eliminated.

Although the wall 55-2 is formed only around the periphery of the opening 43 of the first substrate 31, the wall 55-2 is formed by coating the periphery of the first substrate 31 so as to extend in the direction of the optical elements 35 and 36. The formation corresponding to the protrusion 105 similar to that described in FIG. 16 means that the bonding surface between the first substrate 31 and the coating layer by the coating material 61 is reduced, and the optical module 65-2 Due to the change of the ambient temperature accompanying the operation, the internal stress generated by the expansion and contraction action at this interface is reduced and greatly reduced.

The optical elements 35 and 36 of the first substrate 31 are formed by the second substrate 42 having the adjusted linear expansion coefficient and the covering material 61.
Including the bonding wires on the side, all are integrally coated, so that the optical elements 35 and 36 are not affected by the entry of external light, and the whole also cooperates with temperature changes. Expansion and contraction, based on internal stress fluctuations and differences in expansion and contraction.
Inconvenience such as peeling off at the boundary surface of the substrate 31 does not occur.

FIG. 18 is a side sectional view of a seventh embodiment of the optical module according to the present invention. This embodiment is basically the same as the first embodiment, except that an additional substrate 107 made of, for example, a copper plate having good thermal conductivity is attached to the lower surface of the substrate mounting plate 47. is there.

Therefore, for the portions other than the additional substrate 107, refer to the above description with reference to FIGS. 1 to 5 as necessary. The additional substrate 107 is placed on the substrate mounting plate 47.
Can be mounted in advance by soldering or the like, and after mounting, the interior of the box-shaped substrate 42 is molded.

By adding the additional substrate 107, heat generated due to the operation of the light emitting element (LD chip) 35 is reduced.
A large heat capacity body is formed in cooperation with the substrate mounting plate 107, and heat is radiated to the outside via the box-shaped substrate 42 with heat storage and buffering of generated heat.

FIG. 19 is a side sectional view showing an eighth embodiment of the optical module according to the present invention. This embodiment is basically the same as the first embodiment, except that a heat transfer substrate 108 having good thermal conductivity, for example, a copper plate is attached to the lower surface of the substrate mounting plate 47. It is in.

Therefore, for the portions other than the heat transfer substrate 108, refer to the above description with reference to FIGS. 1 to 5 as necessary. The heat transfer substrate 108 is placed on the substrate mounting plate 47.
Can be mounted in advance by soldering or the like. After the mounting, the box-shaped substrate 42 is molded and molded, and the bottom surface is made the same as the bottom surface of the box-shaped substrate 42 and exposed.

By adding the heat transfer board 108, heat generated by the operation of the light emitting element (LD chip) 35 is reduced.
In cooperation with the substrate mounting plate 47, it becomes a larger heat capacity body, and can directly radiate heat from the bottom surface to the outside with heat storage and buffer action of generated heat. Alternatively, by bringing a heat conductor or a heat radiator into contact with the bottom surface, it is possible to effectively conduct and radiate heat to the outside.

FIG. 20 shows an assembling procedure of the ninth embodiment of the optical module according to the present invention. In this embodiment, the first substrate 31 shown in FIG. 1 is used. Therefore, the above description will be referred to together with FIG. 1, and the description here will be omitted.

The lead frame 111 to which the first substrate 31 is attached has a substrate mounting plate 112 in the center and lead terminals 113 and 114 formed on both sides thereof. It is supported on the frame frames 115 and 116 by processing.

The substrate mounting plate 112 at the center is positioned by being connected and supported by portions extending from the lead terminals 113 on both sides. The frames 115 on both sides are elongated in the extending direction, and such a lead frame 1
Numerals 11 are formed continuously in a large number of bands at equal intervals, and the figure shows only one of them.

Referring to FIG. 21, the first substrate 31 is mounted on the substrate mounting plate 112 of the lead frame 111, and the optical devices 35 and 36 are disposed with the end of the waveguide 33 as the outside.
The lead terminals 113 and 114 are tightly covered and integrated by molding with synthetic resin.

FIG. 21A is a plan view, FIG. 21B is a front view, and FIG. 21C is a side sectional view. Specifically, a metal layer that can be soldered is formed on the lower surface of the first substrate 31 by a metallizing method or the like, and is fixed by soldering on the substrate mounting plate 112 of the lead frame 111.

Next, the bonding pads 38 (FIG. 1) of the first substrate 31 and the lead terminals 113 and 14 are connected by a bonding wire 117 in a predetermined relationship. The optically transparent synthetic resin 58, for example, a silicone resin or an epoxy-based resin, including the vicinity of the optical elements 35 and 36 and the relay bonding pad 37 on the first substrate 31 and on the waveguide 33. Supply and cover.

The step of supplying the optically transparent synthetic resin 58 may be performed before the substrate is placed on the substrate placing plate 112. The end side of the waveguide 33 of the first substrate 31 and the lead terminals 113 and 114
Are positioned and set in a mold, and epoxy resin is cast, integrally covered, cured and taken out, and the frame frames 115 and 116 are cut and removed in the illustrated state as shown.

As the epoxy resin, a resin mixed with short fibers such as glass or carbon for controlling the coefficient of linear expansion is used. In the optical module 65-5, the optical elements 35 and 36 of the first substrate 31 are integrally and densely covered with the synthetic resin 118 including the lead terminals, similarly to the above-described embodiments. Therefore, even if the temperature changes due to the operation, the entire structure expands and contracts, so that the internal stress is averaged and the coating resin does not peel off.

The optical module 65-5 is the same as that shown in FIG. 5B, and can be used in this state. However, as in the embodiment shown in FIG. It is of course sufficiently possible to make the optical module 101 equivalent to the optical module 101 shown in FIG.

FIG. 22 shows an end view of the second embodiment of the first substrate of the present invention in a separated state in FIG. (A) and an assembled state in FIG. (B), and FIG. This is shown in a side view in which the part is broken and shortened.

The first substrate 121 is formed by polishing or etching two upper and lower glass or silicon plates 122 and 123 to form two precise V-grooves 124 and 125. The fiber 126 is fitted, for example, supplied and applied with a UV adhesive, and cured and integrated by irradiation with ultraviolet light, and the end surface is polished to finish the optical surface.

As shown in FIG. 23, the lower plate 123
The optical elements 35 and 36 are mounted on the rear upper surface of the
26 and are mounted so as to be optically coupled to each other. A bonding pad 37 for relay, a bonding pad 38 for connection to an external circuit,
Forming a circuit pattern for connecting the two bonding pads 37 and 38 and connecting them with bonding wires is the same as in FIG.

With the above configuration, the optical module can be handled in the same manner as the first substrate 31 in FIG. 1, and thus the optical module in each of the above-described embodiments can be obtained.

Since the first substrate 121 employs the optical fiber 126 as a waveguide, it is relatively easy to manufacture and has good matching of optical coupling with an optical fiber as an external transmission line. It is.

FIG. 24 shows the results of a temperature cycle test of the optical module of the present invention and a conventional optical module. However, the conventional optical module is not a publicly known one, but is one shown in FIG. 27, which has been researched and prototyped to realize the present invention.

The test conditions were -40 ° C. to + 85 ° C.
The temperature range of C was repeated in units of 2 hours / cycle. The horizontal axis indicates the number of cycles, and the vertical axis indicates the percentage of non-defective products in percent.

As is clear from the drawing, the optical module of the present invention did not cause any abnormality in the 500-cycle test, but the optical module of the conventional configuration already had 25 in one cycle.
%, And all became abnormal after 100 cycles.

FIG. 25 shows the result of a test performed under a high temperature and high humidity condition in a state where the optical module is energized. The test conditions were as follows: operating temperature 85 °
C, humidity 85%. The horizontal axis indicates the test time, and the vertical axis indicates the percentage of non-defective products in percent.

In the optical module of the present invention, no abnormality occurred even after 500 hours, but in the conventional optical module, an abnormality occurred immediately after the start of the test, and an abnormality occurred 60% after 168 hours.

In the present invention, the following embodiments can be applied in addition to those described in each embodiment. That is, the present invention is not limited to the optical coupling between the optical transmission line and the light emitting element (LD, LED) or the light receiving element (PD). Other elements such as an IC chip, an optical switch, and LiNbO
Of course, a combination with 3, etc. is also possible, and these can be sealed with a resin.

Although not described in the embodiment because it is complicated, in the case of the LD, a monitoring LD for monitoring the emitted LD light is arranged on the back side, and the LD is used for monitoring and controlling the LD. It is also included.

In the above description, the optical coupling between the optical element and the optical waveguide is performed directly. However, it is of course possible to arrange a lens system and optically couple through the lens system.

As the first substrate, a metal substrate other than silicon, for example, an epoxy resin substrate, a ceramic substrate, or the like can be used. In the case of a resin substrate, the coefficient of linear expansion is naturally controlled. . Further, as the second substrate, a phenol resin, an epoxy resin, an engineering plastic, or the like having a controlled linear expansion coefficient can be applied. The coefficient of linear expansion of these substrates and the resin of the coating layer is 1
0-100 × 10 ⁻⁶ / ° C.

Although the optical module of the present invention is as described above, each of the embodiments of the present invention is not a single invention, and it is needless to say that the embodiments can be applied to any combination of the embodiments as appropriate. Needless to say, functions and effects unique to each embodiment can be obtained.

[0127]

As described above in detail, according to the optical module of the present invention, since the optical element is optically coupled to the end of the optical transmission line on the first substrate, it is simple and simple. An optical element mounting side of the first substrate is supported on a second substrate, and the second substrate is densely covered with a covering material including an optical transmission line and an optical element to be integrated with each other, so that a wiring material and The lead terminals can easily be hermetically sealed and cooperate to enclose and cover the optical transmission line and the optical element. There will be no occurrence. By controlling the coefficient of linear expansion of each member, more stability against temperature changes can be obtained.

With the optical element side of the first substrate supported on the second substrate, a wall is disposed on the second substrate across the first substrate at the other end of the optical transmission path. Then, the second substrate is densely covered with the covering material including the optical transmission path and the optical element and integrated, so that the covering material shrinks in the process of curing, but the wall to which the covering material adheres is formed. Since the body moves in the shrinking direction, the coating material cracks due to curing shrinkage.
There will be no occurrence.

When the optical transmission line on the first substrate is formed as a buried type laminated structure, the productivity and the positional accuracy of the optical waveguide are improved integrally with the substrate.

By using an optical fiber as the optical transmission line on the first substrate, the matching of the optical coupling with the optical fiber as the external optical transmission line is improved. A substrate having an optical transmission path and an optical element optically coupled to an end of the optical transmission path,
Place and position on the board mounting plate extending from the lead terminal,
Includes the substrate mounting plate, the optical transmission path on the optical element side of the substrate, and the optical element, and covers them tightly with synthetic resin and integrates them into a molded product with good moldability and excellent mass productivity. . By controlling the coefficient of linear expansion of the synthetic resin to be coated, it is possible to eliminate the influence of the temperature change on the substrate.

An optical element which is optically coupled to one end of an optical transmission line is integrated on a substrate by covering it tightly with a synthetic resin, and an optical fiber is optically connected to the substrate at the other end of the optical transmission line and housed in a case. By leading the optical fiber out of the case, optical connection with an external optical circuit can be easily and surely achieved.

Since the optical connection between the optical waveguide on the substrate and the external optical waveguide is an external portion derived from the hermetically sealed portion by the coating layer, the alignment adjustment of the optical connection with the external optical waveguide can be reliably performed. Easy to do.

As described above, according to the optical module of the present invention, various effects are exhibited, and the practical effects are extremely remarkable, such as being stable, excellent in reliability, and good in mass productivity.

[Brief description of the drawings]

FIG. 1 is an external view of a first substrate of the present invention.

FIG. 2 is an external view and a cross-sectional view of a main part of a second substrate according to the present invention.

FIG. 3 is an assembly diagram (part 1) of the first and second substrates of the present invention.

FIG. 4 is an assembly diagram (part 2) of the first and second substrates of the present invention.

FIG. 5 is a side sectional view of the first embodiment of the optical module of the present invention.

FIG. 6 is an external view of an optical module according to a second embodiment of the present invention.

FIG. 7 is an external view and a side sectional view of the optical module housing case of the present invention.

FIG. 8 is an assembly procedure (part 1) of the optical module of the present invention.
It is.

FIG. 9 is an assembly procedure (part 2) of the optical module of the present invention.
It is.

FIG. 10 is an assembly procedure (part 3) of the optical module of the present invention.

FIG. 11 is an assembly procedure (part 4) of the optical module of the present invention.

FIG. 12 is an assembly procedure (part 5) of the optical module of the present invention.

FIG. 13 is an assembly procedure (part 6) of the optical module of the present invention.

FIG. 14 is an external view of an optical module according to a third embodiment of the present invention.

FIG. 15 is an external view of an optical module according to a fourth embodiment of the present invention.

FIG. 16 is a fifth embodiment of the optical module according to the present invention.

FIG. 17 is a sixth embodiment of the optical module of the present invention.

FIG. 18 is a side sectional view of an optical module according to a seventh embodiment of the present invention.

FIG. 19 is a side sectional view of an optical module according to an eighth embodiment of the present invention.

FIG. 20 is an assembly procedure of the ninth embodiment of the optical module of the present invention.

FIG. 21 is a ninth embodiment of the optical module of the present invention.

FIG. 22 is an end view of a second embodiment of the first substrate of the present invention.

FIG. 23 is a side view of a second embodiment of the first substrate of the present invention.

FIG. 24 shows a result of a temperature cycle test of the optical module.

FIG. 25 shows a test result under high temperature and high humidity in an energizing operation state of the optical module.

FIG. 26 is a side sectional view of a conventional optical module.

FIG. 27 is a study prototype for realizing the optical module of the present invention.

[Explanation of symbols]

 Reference Signs List 31 first substrate 31-1 first substrate 32 silicon substrate 33 light transmission path 35 light emitting element 36 light receiving element 37 relay bonding pad 38 bonding pad 39 bonding wire 41 second substrate 42 box-shaped substrate 43 opening portion 45 concave groove portion 46 lead terminal 47 substrate mounting plate 48, 49 lead terminal 51 bonding wire 55 wall 55-1 wall 55-2 wall 56 cutout 58 optically transparent synthetic resin 61 coating material 65 optical module 65 -1 to -5 optical module 66 optical module 66-1 optical module 67 hole 71 accommodating case 71-1 accommodating case 72 optical module accommodating part 73 accommodating part of optical coupling part 75 terminal row through hole 76 columnar projection 77 partition wall 78, 79 Notch 81 Stepped surface 82 Hook 83 Addition means 85 Light Fiber 86 Optical fiber core wire 87,88 Holder 91,92 V-groove 93 Holding bush 94 Flange-shaped part 95 Fitting part 98 Optical connector 97 Lid 97-1 Lid 101,102 Optical module 105 Projecting part 107 Additional substrate 108 Heat transfer substrate 111 Lead frame 112 Substrate mounting plate 113,114 Lead terminal 115,116 Frame frame 117 Bonding wire 118 Synthetic resin 121 First substrate 122,123 plate 124,125 V groove 126 Optical fiber

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04B 10/12 (72) Inventor Eiji Kikuchi 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Kazuhiro Tanaka 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Masahiro Kobayashi 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Akira Fukushima 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Satoru Satoru 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Mitsuo Fukuda Nippon Telegraph and Telephone Corporation 3-1-2-3 Nishi-Shinjuku, Shinjuku-ku, Tokyo Japan Eye # 19 No. 2, Nippon Telegraph and Telephone Corporation in the

Claims (6)

[Claims] A first substrate having an optical transmission line and an optical element optically coupled to one end of the optical transmission line; a plurality of lead terminals; A second substrate made of a synthetic resin that supports the element side together with the optical transmission path; and a cover made of a synthetic resin on the second substrate, including the optical transmission path and the optical element of the first substrate. An optical module, wherein the optical module is densely covered and integrated with a second substrate in cooperation with a material. A first substrate having an optical transmission line and an optical element optically coupled to one end of the optical transmission line; a first substrate having a plurality of lead terminals; A second substrate made of a synthetic resin supporting the element side together with the optical transmission path, and a wall mounted on the second substrate across the first substrate at the other end of the optical transmission path. And that the second substrate is tightly covered and integrated with the second substrate by a covering material made of a synthetic resin including the optical transmission path and the optical element of the first substrate in cooperation with the second substrate. Characteristic optical module. 3. An optical transmission line, comprising: a first substrate having an optical transmission line formed of a laminated optical waveguide, an optical element optically coupled to one end of the optical transmission line, and a plurality of lead terminals. A second substrate made of a synthetic resin that supports the optical element side together with the optical transmission path with the other end of the optical element as the outside, and the optical transmission path of the first substrate and the optical element on the second substrate. An optical module characterized in that it is covered tightly and integrated with a second substrate by a covering material made of a synthetic resin. 4. A first substrate having an optical transmission line composed of an optical fiber, an optical element optically coupled to one end of the optical transmission line, a plurality of lead terminals, and the other end of the optical transmission line. A second substrate made of a synthetic resin that supports the optical element side together with the optical transmission path as an external component, and the second substrate is combined with the optical transmission path of the first substrate and the optical element. An optical module, wherein the optical module is densely covered and integrated with a second substrate in cooperation with a coating material made of a resin. 5. A semiconductor device comprising: a plurality of lead terminals; a substrate mounting plate extending from the lead terminals; an optical transmission path; and an optical element optically coupled to one end of the optical transmission path. The optical transmission path on the optical element side of the substrate and the optical element are covered tightly with a synthetic resin and integrated with the other end side of the optical transmission path as the outside. Optical module. 6. An optical transmission line on a substrate and an optical element optically coupled to one end of the optical transmission line, which are densely covered with synthetic resin and integrated, and an optical fiber is connected to the other end of the optical transmission line. An optical module characterized in that the optical fiber is connected to a housing made of synthetic resin, and the optical fiber is led out of the case.