JPH10300988A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical module which can increase the height of an electron cooler while reducing the height of the case of the optical module by eliminating a component projecting on a metal-plate unmounted surface. SOLUTION: A laser diode is mounted on a metal plate 107 which has vertically penetrating electrode parts 123, a ceramic substrate 115 constituting the top surface of the electron cooler 112 is formed in a channel shape to provided a space part 115A in the center part, and the metal plate 107 is fixed onto the channel-shaped ceramic substrate 116 of the electron cooler 112 with a heat-conductive adhesive so that a Peltier element 117 at the space part 115A is eliminated and the laser diode is arranged at the space part 115A and directed to an optical fiber fixed outside a case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photoelectric conversion element,
The present invention relates to an optical module that optically couples with an optical fiber, and in particular, has an electronic cooler having a function of cooling heat generated from a photoelectric conversion element, and a function of heating and cooling the photoelectric conversion element to a constant temperature. It relates to an optical module.

[0002]

2. Description of the Related Art An optical communication apparatus requires an optical module having a structure in which a photoelectric conversion element such as a light emitting element or a light receiving element is optically coupled to an optical fiber. As an example, there is a device provided with an electronic cooler for cooling heat generated from a photoelectric conversion element.

FIG. 8 is a sectional view of such a conventional optical module, FIG. 9 is a plan view of an electronic cooler of the optical module, and FIG. 10 is a sectional view of the electronic cooler. In these figures, reference numeral 1 denotes a laser diode as a light emitting element (hereinafter, referred to as a light emitting element).
2) LD1 is fixed with solder, and LD1 is
3 is an LD header to which the heat sink 2 is fixed by solder, and 4 is a monitor photodiode (hereinafter abbreviated as monitor PD) as a light receiving element for monitoring the output of the LD 1.

Further, 5 is a PD header to which the monitor PD 4 is fixed by solder, 6 is a thermistor resistor (hereinafter abbreviated as a thermistor) as a temperature detecting means, 7 is a metal plate, and the LD header 3 and PD are provided on the surface. The header 5 and the thermistor 6 are attached by heat fixing or the like for heat radiation. 8 is LD1
This lens has a metal holder, and is fixed to the metal plate 7 by YAG laser or the like after adjusting the optical axes of the lens 8 and the LD 1.

Further, reference numeral 9 denotes an electronic cooler for cooling the heat generated from the LD 1, and as shown in FIGS. 9 and 10, a ceramic substrate 12 having metallized patterns 10, 11 provided on opposing surfaces thereof. 13 and a Peltier effect for cooling, which is sandwiched between the metallization patterns 10 and 11 therebetween (a temperature difference occurs between the upper and lower end surfaces of the element when energized)
(Hereinafter, abbreviated as Peltier element) 14.

Here, the ceramic substrates 12, 13 and the Peltier element 14 are fixed with solder in order to improve the thermal conductivity. Electrical lead wires 15 and 16 made of soft copper or the like are fixed to the metallized patterns 10 and 11 of the ceramic substrates 12 and 13 by soldering. The ceramic substrate 13 is fixed to the back surface of the metal plate 7 by soldering, and the ceramic substrate 12 is fixed to the case 17 by soldering.

The ceramic substrates 12 and 13 are made of Al ₂ O ₃
And AlN are used, and the metallized patterns 10 and 11 are used.
For example, Au is used. The case 17 has a through hole at one end, a butterfly-type structure, and a flat bottom surface.
The structure is such that heat from the high-temperature side of the electronic cooler 9 is conducted to the outside. A metal plate 7 to which an LD header 3, a PD header 5, a thermistor 6, and a lens 8 are attached is housed and fixed in a case 17 integrally with an electronic cooler 9, and is protected.

A ceramic terminal portion 18 is formed at a predetermined height on the inner surface of the case 17.
Are electrically connected to the LD header 3, the PD header 5, and the thermistor 6 by wire bonding or the like.
16 are electrically connected by soldering. After filling the inside of the case 17 with nitrogen gas or the like, the cover 19 is seam-welded and fixed to the case 17 so as to close the upper opening of the case 17. Reference numeral 20 denotes a ferrule, reference numeral 21 denotes an optical fiber, reference numeral 22 denotes a sleeve. The end of the optical fiber 21 is fixed and held at the center of the ferrule 20, and the ferrule 20 is inserted into the sleeve 22. After adjusting the optical axis of the optical fiber 21 with respect to the LD 1 and the lens 8, the ferrule 20 and the sleeve 22 are fixed by welding with a YAG laser or the like, and the sleeve 22 is fixed to the case 17 by welding with a YAG laser or the like. The output light from the LD 1 is focused by the lens 8, irradiated to the end face of the optical fiber 21 whose optical axis has been adjusted to the focal position of the focused beam, and
Optically coupled.

The LD 1 also outputs light from the end face opposite to the lens 8 when outputting light by energization. Monitor PD
By receiving the light at 4, the output power of the LD 1 can be monitored. At the time of this optical coupling, heat generated from the LD 1 is transmitted to the metal plate 7 via the heat sink 2 and the LD header 3, and when the thermistor 6 detects that the metal plate 7 has reached a certain temperature, a detection signal is generated. Is supplied to the electronic cooler 9, the metal plate 7 is cooled by the Peltier element 14, and thus the LD 1 is cooled.

[0010]

However, the structure of the above-mentioned conventional optical module has the following problems.
The metal plate 7 is fixed on the upper part of the electronic cooler 9 and the L
The D header 3, the LD 1, the lens 8, etc. are fixed. The mounting height in the case 17 is determined by the thickness of the metal plate 7, the height of the protruding parts fixed to the mounting surface of the metal plate 7, and the height of the electronic cooler 9. Determined by adding height.

However, the height of the case 17 is limited by the mounting of the device, and if the height of the protruding parts fixed to the metal plate mounting surface cannot be reduced to accommodate the case 17, the thickness of the metal plate 7 must be reduced. And the height of the electronic cooler 9 must be reduced. Reducing the height of the electronic cooler 9 lowers the height of the Peltier element 14, and the element itself generates Joule heat and conducts heat from the high-temperature side, thereby lowering the cooling capacity.

When the ambient temperature increases and the difference from the set cooling temperature increases, the current supplied to the Peltier element 14 increases, and the cooling limit further decreases due to an increase in Joule heat. Under such circumstances, it is difficult to reduce the height of the case 17 and it is difficult to reduce the size. Further, if the cooling capacity of the electronic cooler 9 is limited, there arises a problem that, when the environmental temperature becomes high, the cooling set temperature of the metal plate 7 cannot be lowered, and the usable environmental temperature cannot be set high. There was a problem.

Further, the fact that the cooling set temperature of the metal plate 7 is high is related to the problem that the temperature of the LD 1 becomes high and the long-term reliability is deteriorated. The present invention eliminates the above-mentioned problems, eliminates parts projecting on the metal plate non-mounting surface, reduces the case height of the optical module, and increases the height of the electronic cooler. It is an object of the present invention to provide an optical module that can be used.

[0014]

In order to achieve the above object, the present invention provides: [1] a pair of ceramic substrates having a photoelectric conversion element, a lens, and a metallized pattern in a case; With a semiconductor Peltier element sandwiched between, and fixing an electronic cooler that cools the heat generated from the photoelectric conversion element, the photoelectric conversion element and the electronic cooler to a terminal portion provided in the case In an optical module in which an optical fiber that is electrically connected and optically coupled to the outside of the case via the lens and the photoelectric conversion element is fixed, a metal having a plurality of vertically extending electrode portions (123) The photoelectric conversion element (101) is mounted on a plate (107), and a ceramic substrate (115) constituting the upper surface of the electronic cooler (112) is formed in a U-shape. The space part (115A) is provided in the center part, and the Peltier element (117) of this space part (115A) is eliminated.
The photoelectric conversion element (101) is provided in the space (115A).
And the photoelectric conversion element (10) in the direction of the optical fiber (126) fixed to the outside of the case (120).
The metal plate (107) is fixed on a U-shaped ceramic substrate (115) of the electronic cooler (112) with a thermally conductive adhesive so that 1) faces.

As described above, the space (115A) is provided at the center so that the ceramic substrate (115) on the upper surface of the electronic cooler (112) is formed in a U-shape.
7) LD header (103) and PD header (1)
05) is turned upside down so as to enter the center space (115A), and the mounting surface (108) of the metal plate (107) is
Is fixed to the upper surface of the U-shaped ceramic substrate (115), so that the non-mounting surface (1) of the metal plate (107) is fixed.
Since there is no component protruding at 22), the height of the optical module case (120) can be reduced, and at the same time, the height of the Peltier element (117) can be increased.

[2] A photoelectric conversion element, a lens,
And a pair of ceramic substrates having a metallized pattern, and a semiconductor Peltier element sandwiched between the pair of ceramic substrates, wherein an electronic cooler for cooling heat generated from the photoelectric conversion element is fixed, and the photoelectric conversion is performed. A light in which an element and the electronic cooler are electrically connected to a terminal provided in the case, and an optical fiber optically coupled to the photoelectric conversion element and the lens via the lens is fixed to the outside of the case. In the module, a metal plate (20) having a plurality of electrode portions (207, 208) penetrating vertically
5) The photoelectric conversion element (201) is mounted on the ceramic substrate (217-1 and 21-1), which is a parallel bisecting of the ceramic substrate forming the upper surface of the electronic cooler (213).
7-2), a space (218) is provided in the center, and the Peltier element (219) in the space (218) is eliminated, and the photoelectric conversion element (201) is replaced by the space (21).
8) and the parallel ceramic substrate (217) of the electronic cooler (213) so that the photoelectric conversion element (201) faces the optical fiber fixed to the outside of the case (222). -1, 217-2) on which the metal plate (205) is fixed by a heat conductive adhesive.

As described above, the ceramic substrate on the upper surface of the electronic cooler (213) is divided into two parallel ceramic substrates (2).
17-1 and 217-2), and a space (21
8), and a Peltier element (2) in this space (218).
19), the TWA header (203) and the thermistor (204) mounted on the metal plate (205) are turned upside down so as to enter the space (218).
The mounting surface (206) of 5) and the upper surface of the ceramic substrate (217-1, 217-2) divided into two parts of the electronic cooler (213) are fixed, so that the non-mounting surface of the metal plate (205) is fixed. Since there are no parts protruding at (224), the height of the case of the optical module can be reduced, and at the same time, the height of the Peltier element (219) can be increased.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an optical module showing a first embodiment of the present invention, FIG. 2 is a perspective view of a metal plate of the optical module, FIG. 3 is a mounting view on the metal plate, and FIG. It is an electronic cooler and assembly explanatory drawing.

In these figures, reference numeral 101 denotes a laser diode (hereinafter abbreviated as LD) as a photoelectric conversion element;
Reference numeral 02 denotes a heat sink that fixes the LD 101 with solder and radiates heat generated by the LD 101, and reference numeral 103 denotes an LD header to which the heat sink 102 is fixed with solder. 104 is the LD 101
Monitor PD 105 serving as a light receiving element for monitoring the output of
Are PD headers to which the monitor PD 104 is fixed by soldering, 10
Reference numeral 6 denotes a thermistor as a temperature detecting means.

Reference numeral 107 denotes a metal plate, as shown in FIG. 2, having an electrode portion 123 vertically penetrated electrically. Then, the LD header 103, the PD header 105,
As shown in FIG. 3, the thermistor 106 is fixed to the mounting surface 108 of the metal plate 107 by soldering, and is electrically connected to the electrodes 109 and 110 on the metal plate mounting surface at predetermined positions by wire bonding. .

Reference numeral 111 denotes a lens for condensing the output light of the LD 101, which has a metal holder. After adjusting the optical axes of the lens 111 and the LD 101, a YAG laser is used to mount the metal plate 107 as shown in FIG. It is fixed to the surface 108 by welding. Reference numeral 112 denotes an electronic cooler for cooling the heat generated from the LD 101. As shown in FIG. 4, ceramic substrates 115 and 116 having metallized patterns 113 and 114 provided on opposing surfaces thereof, and a metallized pattern 113 therebetween. , 114, and a Peltier element 117 for cooling. Ceramic substrate 115,
The Peltier element 117 and the Peltier element 117 are fixed with solder in order to improve thermal conductivity. Ceramic substrate 115,
Electrical lead wires 118 and 119 formed of soft copper are fixed to the metallized patterns 113 and 114 by soldering.

As shown in FIG. 4, the ceramic substrate 116 is a flat plate, and the ceramic substrate 115 is
, And has a space 115A at the center. As shown in FIG. 4, the LD header 103, the PD header 105, and the thermistor 106 fixed to the mounting surface 108 of the metal plate 107 enter the central space 115A of the ceramic substrate 115, and the lens 111 faces the opening. To
The mounting surface 108 of the metal plate 107 and the “U” -shaped ceramic substrate 115 of the electronic cooler 112 are fixed by soldering.

The ceramic substrate 116 is fixed to the case 120 with solder. The ceramic substrates 115, 1
For Al ₂ O ₃ , metallized pattern 1 was used.
Au is used for 13,14. Case 120
Has a through hole at one end and has a butterfly-type structure with a flat bottom surface, so that heat from the high-temperature side of the electronic cooler 112 is conducted to the outside.

The LD header 103, PD header 10
5. The metal plate 107 to which the thermistor 106 and the lens 111 are attached is housed and fixed in the case 120 integrally with the electronic cooler 112 and protected. The metallized pattern of Au provided on the ceramic terminal portion 121 formed at a predetermined height on the inner surface of the case 120 and the electrode portion 123 on the non-metal plate mounting surface are electrically connected to predetermined positions by wire bonding. The ceramic terminal portion 121 of the case 120 is electrically connected to the LD header 103, the PD header 105, and the thermistor 106, and the energizing lead wires 118 and 119 of the electronic cooler 112 are electrically connected by soldering.

The cover 124 is fixed to the case 120 by seam welding so as to cover the open portion of the upper surface of the case 120 after filling the inside of the case 120 with nitrogen gas or the like. 125 is a ferrule, 126 is an optical fiber, 127
Is a sleeve, and the end of the optical fiber 126 is fixedly held at the center of the ferrule 125, and the ferrule 125 is inserted into the sleeve 127.

After adjusting the optical axis of the optical fiber 126 with respect to the LD 101 and the lens 111, the ferrule 1
25 and the sleeve 127 are fixed by welding with a YAG laser or the like, and the sleeve 127 is fixed to the case 120 by welding with a YAG laser or the like. The output light from the LD 101 is the lens 1
At 11, the focused beam is irradiated onto the end face of the optical fiber 126 whose optical axis is adjusted to the focal position, and optically coupled to the optical fiber 126.

The LD 101 also outputs light from the end face opposite to the lens 111 when outputting light by energization. By receiving this light with the monitor PD 104, the output power of the LD 101 can be monitored. At the time of this optical coupling, heat generated from the LD 101 is transmitted to the metal plate 107 via the heat sink 102 and the LD header 103,
The thermistor 1 indicates that the metal plate 107 has reached a certain temperature.
When the electric signal is detected by 06, the electric cooler 112 is energized based on the detection signal, the metal plate 107 is cooled by the Peltier element 117, and therefore the LD 101 is cooled.

In the first embodiment described above, the LD 101 is used as the photoelectric conversion element, but the present invention can be applied to other light emitting elements. Further, the present invention can be applied to an optical module in which the light receiving element (monitor PD 104) is mounted at the position of the light emitting element (LD 101) and coupled to the optical fiber 126. In this case, the monitor PD 104 and the PD header 105 become unnecessary. As described above, according to the first embodiment, at least the photoelectric conversion element and the electronic cooler for cooling or stabilizing the heat generated from the photoelectric conversion element are fixed in the case, and the photoelectric conversion element is fixed. In an optical module in which an element and the electronic cooler are electrically connected to a terminal portion provided in the case, and an optical fiber optically coupled to the photoelectric conversion element is fixed to the case, The central portion of the ceramic substrate is formed into a U-shape, and the metal plate is mounted so that the LD header and PD header mounted on the metal plate enter the space at the center of the U-shaped portion of the electronic cooler. By fixing the electronic cooler to the electronic cooler, there are no protruding parts on the metal plate non-mounting surface, and the case height of the optical module can be reduced, and at the same time, the height of the electronic cooler can be increased. Kill.

This is because the projecting parts on the metal plate mounting surface enter the inside of the electronic cooler, so that there are no projecting parts on the metal plate non-mounting surface in the case, and the mounting height in the case is reduced. And the height of the part protruding on the metal plate mounting surface is substantially determined by adding the thickness of the electronic cooler, so that the height of the case can be reduced approximately by the thickness of the electronic cooler.

Further, in order to prevent heat from being transferred by contact of the projecting parts of the metal plate mounting surface in the electronic cooler with the case, it is necessary to increase the height of the electronic cooler. When the height of the electronic cooler increases, the size of the Peltier element can be increased.
Because the effect of heat conduction from the high temperature side can be reduced, the performance of the electronic cooler is improved, and the environmental temperature at which the photoelectric conversion element can be cooled to a constant temperature can be set higher. Cooling can be performed at a low temperature setting, and the long-term reliability of the photoelectric conversion element can be improved.

Next, a second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view of an optical module showing a second embodiment of the present invention, FIG. 6 is a mounting view of the optical module on a metal plate, and FIG. 7 is an explanatory view of assembling an electronic cooler inside the optical module. . In these figures, reference numeral 201 denotes a traveling waveform type optical semiconductor amplifying element (hereinafter, TWA) as a photoelectric conversion element.
Abbreviated as TWA201), and TWA is fixed by soldering.
A heat sink 202 for dissipating heat generated by the heat sink 202; a TWA header 203 to which the heat sink 202 is fixed by soldering; and a thermistor 204 as a temperature detecting means.

Reference numeral 205 denotes a metal plate having an electrode portion 230 vertically penetrated electrically. TWA header 20
3. Thermistor 204 and electrode section 20 on metal plate mounting surface
7, 208 are electrically connected to predetermined positions by wire bonding. Reference numeral 210 denotes a lens for condensing the output light of the input optical fiber 209 and inputting the output light to the TWA 201. The lens 210 has a metal holder.
After adjusting the optical axis of the WA 201, the metal plate 205 is adjusted with a YAG laser.
It is fixed by welding.

Reference numeral 211 condenses the output light of the TWA 201,
A lens for inputting to the output optical fiber 212, which has a metal holder, and has a lens 211 and a TWA2
After the optical axis adjustment of No. 01, it is fixed to the metal plate 205 by welding with a YAG laser. Numeral 213 denotes an electronic cooler for cooling the heat generated from the TWA 201, and as shown in FIG.
And a ceramic substrate 217-1, 217-2 having a space 218
And a Peltier element 219 for cooling, sandwiched between them along a metallization pattern.

Here, the ceramic substrates 216, 217-
1, 217-2 and the Peltier element 219 are fixed with solder to improve thermal conductivity. Ceramic substrate 2
Metallized pattern 2 of 16, 217-1 and 217-2
14 and 215 are energizing lead wires 2 made of soft copper.
20, 221 are fixed with solder. The TWA header 203 and the thermistor 204 fixed to the mounting surface 206 of the metal plate 205 are fixed by solder so as to enter between the ceramic substrates 217-1 and 217-2.

The ceramic substrate 216 is fixed to the case 222 by soldering. The ceramic substrates 216,
Al ₂ O ₃ is used for 217-1 and 217-2, and Au is used for the metallized patterns 214 and 215. The case 222 has through holes at both ends and has a butterfly-type structure with a flat bottom surface, so that heat from the high-temperature side of the electronic cooler 213 is conducted to the outside.

TWA header 203, thermistor 204,
The metal plate 205 to which the lenses 210 and 211 are attached is housed and fixed in the case 222 integrally with the electronic cooler 213.
Is protected. The metallized pattern of Au provided on the ceramic terminal portion 223 formed at a predetermined height on the inner surface of the case 222 and the electrode portion 230 on the non-mounting surface 224 of the metal plate 205 are electrically connected to a predetermined position by wire bonding. By the connection, the ceramic terminal portion 223 of the case 222 is electrically connected to the TWA header 203 and the thermistor 204, and the conducting leads 220 and 221 of the electronic cooler 213 are electrically connected by soldering. .

The cover 225 is fixed to the case 222 by seam welding so that the inside of the case 222 is filled with nitrogen gas or the like, and then the upper opening of the case 222 is closed. 22
Reference numeral 6 denotes a ferrule, 227 denotes a sleeve, and the end of the input optical fiber 209 is fixed and held at the center of the ferrule 226.
Is inserted inside.

After adjusting the optical axis of the input optical fiber 209 with respect to the TWA 201 and the lens 210, the ferrule 22 is adjusted.
6 and the sleeve 227 are fixed by welding with a YAG laser or the like.
The sleeve 227 is fixed to the case 222 by welding with a YAG laser or the like. 228 is a ferrule, 229 is a sleeve, and the end of the output optical fiber 212 is a ferrule 2
28 is fixedly held at the center of the ferrule 2.
28 is inserted into the sleeve 229. After adjusting the optical axis of the output optical fiber with respect to the TWA 201 and the lens 211, the ferrule 228 and the sleeve 229 are fixed by welding with a YAG laser or the like, and the sleeve 229 is fixed with welding to the case 222 with a YAG laser or the like.

The output light from the input optical fiber 209 is focused by the lens 210, and the focal point of the focused beam is set to TW.
Input optical fiber 209 such that the end face of A201 is located
Is adjusted for the optical axis. The output light from the TWA 201 is focused by the lens 211, applied to the end face of the output optical fiber 212 whose optical axis is adjusted to the focal position of the focused beam, and optically coupled to the output optical fiber 212.

An optical signal input from the input optical fiber 209 to the TWA 201 is amplified inside the TWA 201 and output from the output optical fiber 212. The amplification factor of the TWA 201 is controlled by the supplied current. During this optical coupling, heat generated from the TWA 201 is transferred to the heat sink 20.
When the thermistor 204 detects that the temperature of the metal plate 205 has reached a certain temperature, the electric cooler 213 is energized based on the detection signal and the Peltier The metal plate 205 is cooled by the element 219, and thus the TWA 201 is cooled.

In the second embodiment, the TWA 201 is used as a photoelectric conversion element. However, temperature control is required for an optical function element having a photoelectric conversion element such as an optical switch or an optical modulator or an optical integrated circuit element. Optical fiber 209 at both ends of the element
The present invention can also be applied to an optical module to which the 212 is coupled. As described above, according to the second embodiment, at least the photoelectric conversion element and the electronic cooler for cooling or stabilizing the temperature generated from the photoelectric conversion element are fixed in the case, and the photoelectric conversion element And an electronic module in which the electronic cooler is electrically connected to a terminal portion provided in the case and an optical fiber optically coupled to a photoelectric conversion element is fixed to the case. By dividing the ceramic substrate into two and providing a space in the center, and fixing the metal plate to the electronic cooler so that the TWA header mounted on the metal plate enters the space in the center of the cooler, There is no projecting part on the upper surface of the metal plate, and the case height of the optical module can be reduced, and at the same time, the height of the electronic cooler can be increased.

This is because the protruding parts on the metal plate mounting surface enter the inside of the electronic cooler, so that there are no protruding parts on the non-metal plate mounting surface in the case, and the mounting height in the case is reduced. And the height of the part protruding on the metal plate mounting surface is substantially determined by adding the thickness of the electronic cooler, so that the height of the case can be reduced approximately by the thickness of the electronic cooler.

Also, in order to prevent the projecting parts on the upper surface of the metal plate from entering the electronic cooler from contacting the case and transferring heat, it is necessary to increase the height of the electronic cooler. When the height of the cooler is increased, the size of the Peltier element can be increased, and the effects of Joule heat during conduction and heat conduction from the high-temperature side can be reduced. The environmental temperature at which the conversion element can be cooled to a certain temperature can be set higher, and the photoelectric conversion element can be cooled at a lower temperature setting at the same environmental temperature, so that the long-term reliability of the photoelectric conversion element can be improved.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0045]

As described above in detail, according to the present invention, there are no parts projecting on the metal plate non-mounting surface, and the case height of the optical module can be reduced, and at the same time, the height of the electronic cooler can be reduced. The size can be increased. Therefore, the Peltier element can be enlarged, and the influence of Joule heat during energization and heat conduction from the high temperature side can be reduced, so that the cooling capacity of the electronic cooler is improved and the photoelectric conversion element can be cooled to a constant temperature. The environmental temperature can be set higher, and the photoelectric conversion element can be cooled at a lower temperature setting at the same environmental temperature, so that the long-term reliability of the photoelectric conversion element can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an optical module showing a first embodiment of the present invention.

FIG. 2 is a perspective view of a metal plate of the optical module according to the first embodiment of the present invention.

FIG. 3 is a view showing a mounting of an optical module on a metal plate according to the first embodiment of the present invention.

FIG. 4 is an explanatory view of assembling the electronic cooler inside the optical module and showing the first embodiment of the present invention.

FIG. 5 is a sectional view of an optical module showing a second embodiment of the present invention.

FIG. 6 is a view showing a mounting of an optical module on a metal plate according to a second embodiment of the present invention.

FIG. 7 is an explanatory view of assembling an electronic cooler inside an optical module according to a second embodiment of the present invention.

FIG. 8 is a sectional view of a conventional optical module.

FIG. 9 is a plan view of an electronic cooler of a conventional optical module.

FIG. 10 is a cross-sectional view of a conventional electronic cooler of an optical module.

[Explanation of symbols]

Reference Signs List 101 laser diode (LD) [photoelectric conversion element] 102, 202 heat sink 103 LD header 104 monitor PD 105 PD header 106, 204 thermistor 107, 205 metal plate 108, 206 mounting surface of metal plate 109, 110, 207, 208 metal plate Electrodes on mounting surface 111, 210, 211 Lens 112, 213 Electronic cooler 113, 114, 214, 215 Metallized pattern 115 U-shaped ceramic substrate 115A, 218 Space 116, 216 Ceramic substrate 117, 219 Peltier element 118 , 119, 220, 221 energizing lead wire 120, 222 case 121, 223 ceramic terminal part 122, 224 non-mounting surface of metal plate 123, 230 electrode part 124, 225 cover 125, non-metal plate mounting surface 26,228 ferrule 126 optical fiber 127,227,229 sleeve 201 traveling-wave type optical semiconductor amplifier device (TWA) 203 TWA header 209 input optical fiber 212 output optical fiber 217-1,217-2 2 minutes ceramic substrate

Claims (2)

[Claims] A pair of ceramic substrates having a photoelectric conversion element, a lens, and a metallized pattern in a case;
A semiconductor Peltier element sandwiched between the pair of ceramic substrates is provided, and an electronic cooler for cooling heat generated from the photoelectric conversion element is fixed, and the photoelectric conversion element and the electronic cooler are provided in the case. A plurality of electrode portions vertically penetrated in an optical module in which an optical fiber electrically connected to a provided terminal portion and optically coupled to the outside of the case via the lens and the photoelectric conversion element is fixed; The photoelectric conversion element is mounted on a metal plate having, a ceramic substrate forming the upper surface of the electronic cooler is formed in a U-shape, and a space is provided in the center, and a Peltier element of the space is provided. The U-shaped ceramic of the electronic cooler is disposed so that the photoelectric conversion element is disposed in the space and the photoelectric conversion element is oriented in the direction of the optical fiber fixed to the outside of the case. An optical module, wherein the metal plate is fixed on a work substrate by a heat conductive adhesive. 2. A pair of ceramic substrates having a photoelectric conversion element, a lens, and a metallized pattern in a case;
A semiconductor Peltier element sandwiched between the pair of ceramic substrates is provided, and an electronic cooler for cooling heat generated from the photoelectric conversion element is fixed, and the photoelectric conversion element and the electronic cooler are provided in the case. A plurality of electrode portions vertically penetrated in an optical module in which an optical fiber electrically connected to a provided terminal portion and optically coupled to the outside of the case via the lens and the photoelectric conversion element is fixed; The photoelectric conversion element is mounted on a metal plate having: a ceramic substrate constituting the upper surface of the electronic cooler as a parallel bisected ceramic substrate; Eliminating the element, the photoelectric conversion element is disposed in the space,
The metal plate is fixed by a thermally conductive adhesive on a parallel bisected ceramic substrate of the electronic cooler so that the photoelectric conversion element is oriented in a direction of an optical fiber fixed to the outside of the case. Optical module characterized by the above-mentioned.