JP2000081523A - Thin type optical waveguide module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a space from the viewpoint of an arrangement by making it possible to properly control the temperature of a planer optical waveguide part even if it is thin-type. SOLUTION: This module 1 is a thin type optical waveguide module which is provided at least with planar optical waveguide parts 2, a temperature sensor 5 to detect the temperatures of the planer optical waveguide parts, a 1st plane 6a and a 2nd plane 6b and houses a temperature control element 6 to control the temperature of the planar optical waveguide parts inside a package 7. Here, the temperature control element 6 is arranged so that the 1st plane 6a is brought in close contact with the inner face of the package 7 via a 1st heat conductive material and the 2nd plane 6b is brought in close contact with the planar optical waveguide parts 2 via a 2nd heat conductive material, respectively and a thermal insulation layer LI is formed between the planar optical waveguide parts and the package in the direction of the thickness of the package 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin optical waveguide module used for an optical communication system, an optical information processing device, and the like.

[0002]

2. Description of the Related Art A planar optical waveguide component has a function of demultiplexing a signal according to the wavelength of an optical signal, but the demultiplexing performance is affected by temperature. For this reason, in order to keep the temperature constant during use, the planar optical waveguide component is housed in a package using a temperature control element such as a Peltier element and is modularized. Here, usually, the temperature of the planar optical waveguide component is controlled to about 45 ° C. by the temperature control element from the performance of the adhesive used and the like.

Therefore, in a modularized planar optical waveguide component, for example, when the ambient temperature becomes higher than 45 ° C., the temperature control element removes heat from the planar optical waveguide component and releases the heat to the package. I do. On the other hand, when the environmental temperature is lower than 45 ° C., the temperature control element removes heat from the package and gives this heat to the planar optical waveguide component.

[0004] For this reason, the package needs to efficiently radiate heat to the outside or absorb the heat from the outside. Therefore, fins for heat dissipation and heat absorption may be attached to the package.

[0005]

The conventional modular optical waveguide component has a thickness of 20 mm.
Before and after. For this reason, the conventional planar optical waveguide component is:
When used in an optical communication system or an optical information processing device, when mounting on a board and attaching to a bus, two spaces (slots) are required, and the size of the optical communication system or the optical information processing device increases. There was a problem that it would.

In this case, simply reducing the thickness of the package increases the amount of heat that enters and exits from the outside when the temperature difference between the environmental temperature and the control temperature of the planar optical waveguide component increases. In some cases, the temperature control of the optical waveguide component cannot be performed. The present invention has been made in view of the above points, and a thin optical waveguide module capable of appropriately controlling the temperature of a planar optical waveguide component even though it is thin, and capable of saving space in arrangement. The purpose is to provide. In particular, even when the optical waveguide module is mounted on a board mounting bus, the thin optical waveguide module requires only one slot space by adopting a package structure capable of controlling the temperature of the planar optical waveguide component even when the optical waveguide module is thin. The purpose is to realize.

[0007]

According to the present invention, in order to achieve the above object, at least a planar optical waveguide component,
A thin optical waveguide module having a temperature sensor for detecting the temperature of the planar optical waveguide component, and a temperature control element having first and second surfaces for adjusting the temperature of the planar optical waveguide component housed in a package. The temperature control element may be configured such that the first surface is provided on the inner surface of the package via a first heat conductive material, and the second surface is provided on the planar optical waveguide component or a second heat conductive material. The planar optical waveguide component is arranged in close contact with the planar optical waveguide component, and a heat insulating layer is formed between the planar optical waveguide component and the package in the thickness direction of the package.

Preferably, the heat insulating layer has a thickness of 0.8 mm.
As described above, the package in which the first surface of the temperature control element is disposed in close contact with the package has a thickness of 0.2 mm or more, and the total thickness of the heat insulating layer and the package is 7 mm or less. The thickness is 9 mm or less. Here, in this specification, the thermally conductive material refers to an adhesive having thermal conductivity, a soaking plate, a copper plate, an aluminum plate, silicone grease, or the like.

[0009]

When a flat optical waveguide component is controlled to a constant temperature in a thin optical waveguide module, the temperature difference for controlling is different between when the environmental temperature is higher and lower than the control temperature. Requires different power. That is, even if the absolute value of the difference between the set control temperature and the environmental temperature is the same, when the environmental temperature is lower than the set control temperature, heat generated from the temperature control element is also added, so that the temperature of the planar optical waveguide component is increased. Control is easy. On the other hand, when the environmental temperature is higher than the set control temperature, heat generated from the temperature control element must be absorbed from the planar optical waveguide component together, so that more power is consumed than when the environmental temperature is low. Required, making temperature control difficult.

[0010] This fact is also shown in the following equation that is generally used for the amount of heat absorption and heat dissipation of the temperature control element (see FIG. 6). | Qc | = αe · Tcj · I−0.5re · I ² −Ke · ΔTj (Equation 1) qh = αe · Thj · I + 0.5re · I ² −Ke · ΔTj (Equation 1) 2) qc: Heat absorption (W) of the temperature control element, qh: Heat release (W) of the temperature control element αe: Relative thermal conductivity (V / K), Ke: Heat conductance (W / K) I: Control current (A), ΔTj: heat-absorbing / radiating surface temperature difference (K) re: electric resistance (Ω), Tcj: heat-absorbing surface temperature (K) Thj: heat-radiating surface temperature (K)

At this time, the heat re · I ² generated by the temperature control element shown in FIG. 6 acts to reduce the amount of heat absorption qc as shown in equation 1, whereas the heat re · I ² as shown in equation 2 , And acts to increase the heat radiation amount qh. That is, when the planar optical waveguide component is on the heat dissipation surface side, the more the current flows through the temperature control element, the more the planar optical waveguide component is heated. However, when the planar optical waveguide component is on the heat absorbing surface side, if too much current is passed, the temperature control element cannot absorb heat and instead generates heat, which may make it impossible to control the temperature of the planar optical waveguide component. appear.

For this reason, when designing a thin optical waveguide module, it is assumed that the environmental temperature is higher than the control temperature of the planar optical waveguide component, and the temperature control is performed even when the temperature difference is the largest. It is common to design to be able to. Therefore, for example, in a thin optical waveguide module having a thickness of 9 mm, when the environmental temperature is higher than the control temperature of the planar optical waveguide component, as shown in FIG.
Heat is taken from the planar optical waveguide component by the temperature control element to cool the planar optical waveguide component by an amount greater than the amount of heat flowing from the outside. At this time, since most of the heat flowing into the module from the outside passes through the planar optical waveguide component, the maximum value Qc (W) of the heat input can be approximated by the following equation.

Qc = X · Y · λ (Th−Tcj) / t (Expression 3) X: Length (m) of the planar optical waveguide component in the first direction (longitudinal direction) Y: Length (m) in a direction (horizontal direction) orthogonal to direction 1 (longitudinal direction) t: Average thickness (m) of heat insulating layer formed in thickness direction of package λ: Thermal conductivity of heat insulating layer ( W / m · K) Th: maximum temperature of use environment (K) Tcj: set control temperature (K) Here, in a normal thin optical waveguide module, the lengths X and Y of the planar optical waveguide component are 40 mm ( 0.04mm)
Before and after, the maximum temperature Th of the use environment is 70 ° C. (343 K), and the set control temperature Tcj of the planar optical waveguide component is 40 ° C. (313 K).
K), and the heat insulating layer is often air, and the thermal conductivity λ of the air is about 0.02 (W / m · K).

Therefore, in the ordinary thin optical waveguide module, the maximum value Qc (W) of the heat input is as follows. Qc = 9.6 × 10 ⁻⁴ / t (Equation 4) Further, assuming that the heat radiation amount of the temperature control element is qh (W) and the thermal resistance of the heat radiation fin is Rh (K / W), Th in Equations 1 and 2
j and ΔTj are represented by the following equations, respectively. Thj = Th + Rh · qh, ΔTj = Th + Rh · qh−Tcj

Therefore, when these are substituted into Expressions 1 and 2, Expressions 5 and 6 shown below are obtained. | Qc | = αe · Tcj · I−0.5re · I ² −Ke (Th + Rh · qh−Tcj) (Equation 5) qh = ｛αe · Th · I + 0.5re · I ² −Ke (Th− Tcj)｝ / (1−αe · Rh · I + Ke · Rh) (Equation 6) Also, the current flowing through the temperature control element is usually at most about 1 (A), and the relative thermal conductivity αe ( V / K) is 1 × 10 ⁻³ or more.
The thermal resistance Rh (K / W) of the radiation fins is about 5 × 10 ⁻² depending on the design of the package, but usually does not exceed 10 (K / W). Therefore, in Expression 6, 1 + K
Since e · Rh is sufficiently larger than αe · Rh · I, there is no practical problem even if the denominator is expressed as follows. 1−αe · Rh · I + Ke · Rh ≒ 1 + Ke · Rh (Equation 7)

At this time, equation (5) is a simple quadratic equation for I, and for a specific I, the maximum value qcmax
have. qcmax = [(1 + Ke · Rh) ｛αe · Tcj−Ke · Rh · αe · Th / (1 + Ke · Rh)｝ ² ] / 2re (1 + 2Ke · Rh) −Ke (Th−Tcj) / (1 + Ke · Rh) (Expression 8) If qcmax is smaller than Qc in Expression 3, the planar optical waveguide component cannot be maintained at the desired set control temperature Tcj (K). Therefore, qcmax ≧ Qc needs to be satisfied as a requirement of a package that can control the planar optical waveguide component to a desired set control temperature Tcj (K), and the following equation is obtained. [(1 + Ke · Rh) ｛αe · Tcj−Ke · Rh · αe · Th / (1 + Ke · Rh)｝ ² ] / 2re (1 + 2Ke · Rh) −Ke (Th−Tcj) / (1 + Ke · Rh) ≧ λ · X · Y (Th−Tcj) / t (Equation 9)

In Equation 7, since the left side is always smaller than the right side, the value of qh in Equation 6 is actually slightly larger. As a result, qcmax in Equation 8 is slightly smaller than the actual value, and the difference can be secured as a margin for design. For this reason, by applying Equation 9 to the design, a thin optical waveguide module that is efficient and secures a margin is developed.

For example, when mounting a thin optical waveguide module on a device, the radiation fins provided on the package cannot be infinitely large due to the limitation of the arrangement space. For this reason,
Normally, in a thin optical waveguide module, the heat radiation area of the package is about 120 cm ² , and the thermal resistance Rh is about 5 (K / W) in the case of a copper package having a thickness of 1 mm from the relationship shown in FIG.
Becomes As described above, usually, in the thin optical waveguide module, the maximum temperature Th of the use environment is 70 ° C. (343 ° C.).
K), the set control temperature Tcj of the planar optical waveguide component is 40
° C (313K), thermal conductance K of temperature control element
e, electric resistance re, and relative thermal conductivity αe actually vary. However, among the existing and commercially available thin optical waveguide modules, the maximum value qcmax of the specific heat absorption amount is large,
Electric resistance re = 0.98 (Ω), relative thermal conductivity αe = 0.01
(V / K), thermal conductance Ke = 0.054 (W /
K). Therefore, when these numerical values are substituted into (Equation 8), the maximum value qcmax of the heat absorption amount is calculated as follows. qcmax = 1.15 (W)

At this time, since Qc must be smaller than qcmax, the range of t is obtained from (Equation 4) as follows. t> 8.35 × 10 ⁻⁴ Therefore, in the thin optical waveguide module, the minimum thickness of the heat insulating layer is practically about 0.8 (mm).

In the thin optical waveguide module, when the length of the surface where the temperature control element and the package are in contact with each other is L and the width is X, the package material at that portion has a thickness Z.
If the thermal conductivity of the copper is λ _Cu , the thermal resistance Rh at that portion can be approximated as follows. Rh = (L / 2XZ) / λ _Cu At this time, even among the relatively small temperature control elements on the market, L = X = about 5 (mm) and the thermal conductivity of copper is λ _Cu = 400. (W / mK), so that the thermal resistance Rh does not exceed the aforementioned thermal resistance 5 (K / W), Z> 0.2.
5 (mm). That is, in the thin optical waveguide module, it is actually necessary to secure a thickness of at least about 0.2 (mm) in a portion where the temperature control element is in contact.

[0021] The temperature control element is usually 1 mm or more in thickness even if it is commercially available, and the same applies to optical waveguide parts. Therefore, in the thin optical waveguide module, it is necessary that the total of the thickness t of the heat insulating layer and the thickness Z of the package at a portion in contact with the temperature control element is 7 mm or less, and the total thickness of the package is 9 mm or less. Therefore, the object of the present invention can be achieved by providing a thin optical waveguide module satisfying such conditions.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIGS. Thin optical waveguide module (hereinafter simply referred to as “optical waveguide module”) 1
As shown in FIGS. 1 and 2, at least a planar optical waveguide component (hereinafter, simply referred to as “optical waveguide component”) 2, a temperature sensor 5, and a temperature control element 6 are housed in a package 7.

The optical waveguide component 2 is a planar optical waveguide component in which a waveguide of a desired pattern is formed on a substrate, and a plurality of input fibers 3a and output fibers 4a are provided on both sides.
Are connected to the optical connectors 3 and 4 attached to the ends of the optical connectors. As shown in FIG. 2, the optical waveguide component 2 is disposed in close contact with a second surface 6 b of a temperature control element 6 described later, and forms a heat insulating layer LI for air between the optical waveguide component 2 and the cover 10 of the package 7.

The temperature sensor 5 is a thermistor for detecting the temperature of the sensor, and is attached to the upper surface of the optical waveguide component 2 by bonding. The temperature sensor 5 transmits a temperature signal to an external control device (not shown) via two electric wires 5a. As shown in FIG. 2, for example, a Peltier element having a first surface 6a is adhesively fixed to a metal base 8 described later. As shown in FIG. 1, the operating current is supplied to the temperature control element 6 from two electric wires 6 c extending outside the package 7. The temperature control element 6 has a first surface 6a bonded to a concave portion 8a of a metal base 8 described later, and a second surface 6b bonded to a lower surface of the optical waveguide component 2 with an adhesive having thermal conductivity.

The package 7 has a metal base 8, a protective case 9 and a cover 12, has a total thickness of 9 mm or less, and FIG. 1 shows a state in which the cover 12 is removed.
Is formed from a material having excellent thermal conductivity, such as copper or aluminum, and functions as a heat sink.
The metal base 8 is provided with a position for positioning the temperature control element 6 substantially at the center, and a plurality of radiating fins 8b are integrally formed on both sides.

The protective case 9 is formed in a frame shape from a synthetic resin such as polyethylene terephthalate (PET), attached to the metal base 8 and accommodated in the package 7 together with the cover 12 in the package 7. Protect etc. The protective case 9 has a concave groove 9a formed along the frame shape at the upper and lower portions, and a heat insulating plate 9c having an opening 9b near the lower portion. The opening 9b is formed larger than the outer shape of the temperature control element 6 so as not to interfere with the heat insulating plate 9c when the temperature control element 6 is disposed in the recess 8a of the metal base 8. The heat insulating plate 9c is
To prevent the heat to be radiated to the outside from the radiating fins 8b of the metal base 8 from being conducted to the optical waveguide component 2 again by convection of air or the like. In addition, protection case 9
As shown in FIG. 1, fixing members 10 are attached to both left and right sides. Each fixing member 10 has an opening 10a formed on the rear side and a concave groove 10b having the same shape at a position continuous with the concave groove 9a on the upper surface, and fixes the rubber boot 11 to the protective case 9. As shown in FIG. 2, seal rings 8c and 12a are arranged in the concave grooves 9a and 10b. The rubber boot 11 protects the plurality of input fibers 3a and output fibers 4a extending from the package 7 from bending so as not to be disconnected.

The cover 12 is a plate made of a synthetic resin such as polyethylene terephthalate (PET).
Over the seal ring 12a. In the optical waveguide module 1 configured as described above, the temperature control element 6 has a relative thermal conductivity αe = 0.01 (V / K), a thermal conductance Ke = 0.054 (W / K), and an electric resistance re = 0.9
8 (Ω), and the metal base 8 is made of copper and has a thickness of 1
mm, and the heat radiation area of the radiation fin 8b is about 80 cm ² , the thermal resistance Rh is about 7 (K / W) from FIG. Here, FIG. 3 is a characteristic diagram showing the relationship between the heat dissipation area (cm ² ) and the thermal resistance by changing the material (copper, aluminum) and the thickness of the metal base 8.

The optical waveguide component 2 has a length X = 4 cm (= 4 × 10 ⁻² m) in the direction of arrow X in FIG. 1 and a length Y = 3 cm (3 in the direction Y perpendicular to the direction of arrow X).
× 10 ^-2 m), and the average thickness t =
1 mm (1 × 10 ⁻³ m), and set control temperature Tcj = 40
° C (≒ 313K). At this time, the heat insulation layer LI is
Since it is air, the thermal conductivity λ = about 0.02 (W / mK)
The maximum temperature of the use environment was Th = 70 ° C. (≒ 343K).

Therefore, the maximum value Qc of the heat input can be obtained from the above equation (3).
(W) is obtained as follows. Qc = 0.04 × 0.03 × 0.02 × (343-313) /0.0.
001 = 0.72 (W) The maximum value qcmax of the heat absorption qc (W) in the temperature control element 6 is qcmax = 0.80 (W) from Expression 8. Therefore, qcmax> Qc, and the expression 9 is satisfied. Since the entire thickness of the optical waveguide module 1 at the time of completion, that is, the entire thickness of the package 7 is 9 mm or less, appropriate temperature control is possible even if the optical waveguide module 1 is thin, and an optical communication system and optical information When used in a processing device or the like, space saving in arrangement can be achieved.

Next, the second embodiment of the optical waveguide module of the present invention will be described.
An embodiment will be described. Optical waveguide module 20
Are optical waveguide components 21, heat equalizing plates 24, as shown in FIG.
Temperature sensor 25 and temperature control element 26 are package 27
The whole is assembled to a thickness of 9 mm or less. Here, in the optical waveguide module described below, the detailed description of the members having the same configuration as the optical waveguide module 1 shown in FIGS. .

The optical waveguide component 21 is connected to optical connectors 22 and 23 attached to the ends of a plurality of input fibers 22a and output fibers 23a on both sides.
The optical waveguide component 21 is bonded and fixed to a heat equalizing plate 24, and forms a heat insulating layer LI for air between the optical waveguide component 21 and a metal base 28 of the package 27 described later. The heat equalizing plate 24 is attached to a later-described upper cover 29 of the package 27 by plastic screws 24a. The temperature sensor 25 is disposed in a concave portion provided on the optical waveguide component 21 side of the heat equalizing plate 24.

The temperature control element 26 has a first surface 26a adhered to an inner surface of an upper cover 29, which will be described later, with an adhesive having thermal conductivity, and a second surface 26b with the optical waveguide component 21 via a heat equalizing plate 24. Each is closely arranged. Package 2
Reference numeral 7 denotes a metal base 28 and an upper cover 29 which are each formed of a material having excellent thermal conductivity such as copper or aluminum and function as a heat sink. The metal base 28 has a plurality of radiating fins 28b integrally formed on both sides, and the upper cover 29 is attached via a rubber boot 27a.

In the optical waveguide module 20 configured as described above, the temperature control element 26 contacts the upper cover 29,
It is also in thermal contact with the metal base 28. Therefore, the heat dissipation area of the optical waveguide module 20 is larger than that of the optical waveguide module 1. For this reason, even if the optical waveguide module 20 has the same thickness as the optical waveguide module 1, the length of the radiation fin 28b can be shortened.

At this time, in the optical waveguide module 20, the temperature control element 26 has a relative thermal conductivity αe = 0.025 (V /
K), a thermal conductance Ke = 0.0056 (W / K), and an electric resistance re = 6.75 (Ω). The metal base 28 is made of copper and has a thickness of 1 mm.
Assuming that the heat radiation area is approximately 200 cm ² , the thermal resistance Rh is as shown in FIG.
From this, Rh = approximately 4 (K / W).

On the other hand, the optical waveguide component 21 has a vertical and horizontal length of X and Y = 4 cm (= 4 × 10 ⁻² m), respectively, and an average thickness t = 1 mm (1 × 1) of the heat insulating layer LI. 10 ⁻³ m), and the set control temperature Tcj was set at 45 ° C. (≒ 318 K). At this time, since the heat insulation layer LI is air, the thermal conductivity λ is about 0.02 (W / m · K), and the maximum temperature of the use environment is Th.
= 70 ° C (≒ 343K).

Accordingly, the maximum value Qc of the heat input can be obtained from the above equation (3).
(W) is obtained as follows. Qc = 0.04 × 0.04 × 0.02 × (343-318) /0.0.
001 = 0.80 (W) Here, in the optical waveguide module 20, the metal base 28 is formed integrally with the radiation fins 28b, and its temperature is considered to be slightly higher than the ambient temperature. Is 75 ° C., the maximum value Qc (W) of the heat input amount is as follows, and there is no large difference. Qc = 0.04 × 0.04 × 0.02 × (348-318) /0.0.
001 = 0.96 (W)

The heat absorption q in the temperature control element 26
The maximum value of c (W), qcmax, is obtained from Equation 8 as qcmax = 1.514.
(W). Therefore, qcmax> Qc, and the expression 9 is satisfied. However, in the optical waveguide module 20, heat is transmitted from the plastic screw 24a to the optical waveguide component 21. Therefore, regarding the optical waveguide module 20, the thermal conductivity of the plastic is 0.2 (W · mK), the diameter of the screw 24a is 2 (mm), and the heat equalizing plate 24 is removed from the inner surface 29a of the upper cover 29.
Assuming that the distance from the screw 24a is 2 (mm), the number of screws 24a is 4, and the temperature of the upper cover 29 is 80 ° C., the heat input from the screw 24a is obtained as shown in the following equation. There is no. ^{{0.2 × π × 0.001 2 ×} (353-318)} / 0.00
2 x 4 = 0.044 (W)

Therefore, the entire thickness of the optical waveguide module 20 when completed, that is, the total thickness of the package 27 is 9
mm or less, appropriate temperature control is possible even in a thin configuration, and space saving in arrangement can be achieved when used in an optical communication system, an optical information processing device, or the like.

Further, the third aspect of the optical waveguide module of the present invention
An embodiment will be described. Optical waveguide module 30
As shown in FIG. 5, an optical waveguide component 31, two heat equalizing plates 34, a temperature sensor 35, and a temperature control element 36 are housed in a package 37, and the whole is assembled to a thickness of 9 mm or less. The optical waveguide component 31 is connected to optical connectors 32 and 33 attached to ends of a plurality of input fibers 32a and output fibers 33a on both sides. The optical waveguide component 31 is sandwiched between two heat equalizing plates 34, and is filled with a heat insulating agent such as a rubber sponge between the package 37 and a metal base 38 described later to form a heat insulating layer LI.

The two heat equalizing plates 24 are arranged on both sides.
It is supported on a metal base 38 by two temperature control elements 36. The temperature sensor 35 is connected to the heat equalizing plate 3 disposed on the lower side.
4 is disposed in a concave portion provided on the optical waveguide component 31 side. The temperature control element 36 has a first surface 36a adhered to an inner surface of a metal base 38, which will be described later, by an adhesive having thermal conductivity, and a second surface 36b is closely attached to the optical waveguide component 31 via the heat equalizing plate 34. Is done.

The package 37 is formed of a material having excellent thermal conductivity such as copper or aluminum, and has a metal base 38 functioning as a heat sink and an upper cover 39 made of a synthetic resin such as polybutylene terephthalate (PBT). are doing. The metal base 38 has a plurality of heat dissipating fins 38b integrally formed on both sides thereof.
The upper cover 39 is attached via 7a.

In the optical waveguide module 30 configured as described above, the thickness of the package 37 is not so much restricted as compared with the optical waveguide modules 1 and 20 in the thickness of the temperature control element 36. For this reason, in the optical waveguide module 30, the selection of the temperature control element 36 is relatively free compared to the optical waveguide modules 1 and 20, and the thickness of the heat insulating layer LI can be increased.

On the other hand, in the optical waveguide module 30, the size of the two heat equalizing plates 34 related to the heat input is larger than that of the optical waveguide component 31.
Use the dimensions of Further, since the optical waveguide module 30 has two temperature control elements 36 and two upper and lower heat input surfaces, the thickness of the heat insulating layer LI, the area of the optical waveguide component 31, the maximum absorption qc of the temperature control element 36 are obtained. The maximum value qcmax of (W) is doubled.

At this time, in the optical waveguide module 30, the temperature control element 36 has a relative thermal conductivity αe = 0.012 (V /
K), heat conductance Ke = 0.083 (W / K), electric resistance re = 0.89 (Ω), and the metal base 38 is made of aluminum, having a thickness of 2 mm, and a radiation area of the radiation fins 38b. Is about 150 cm ² , the thermal resistance Rh is about 5 (K / W) from FIG.

On the other hand, the heat equalizing plate 34 has a length and width of 3 cm.
× 4 cm, the average thickness of the heat insulating agent is 3 mm (3 × 10
^-3 m), the thermal conductivity was about 0.05 (W · mK), and the set control temperature of the optical waveguide component 31 was set to Tcj = 50 ° C. (≒ 323 K). At this time, the maximum temperature of the use environment of the optical waveguide module 30 was Th = 90 ° C. (≒ 363 K). Therefore, the maximum value Qc (W) of the heat input is obtained from the above equation 3 as follows. Qc = 0.03 x 0.04 x 0.05 x 2 x (363-323)
/(0.003×2)=0.8(W)

The heat absorption q in the temperature control element 36
From Equation 8, the maximum value qcmax of c (W) is calculated as qcmax = 0.71.
(W) × 2 = 1.42 (W). Therefore, qcmax> Qc, and the expression 9 is satisfied. Therefore, the optical waveguide module 30
Since the total thickness at the time of completion, that is, the total thickness of the package 37 is 9 mm or less, appropriate temperature control is possible even if the package is thin, and it can be used for an optical communication system, an optical information processing device, or the like. In addition, space saving in arrangement can be achieved.

It should be noted that the thin optical waveguide module of the present invention
It is sufficient that the package contains at least a planar optical waveguide component, a temperature sensor for detecting the temperature of the planar optical waveguide component, and a temperature control element for adjusting the temperature of the planar optical waveguide component. Needless to say, it may be stored.

[0048]

According to the first and second aspects of the present invention, it is possible to appropriately control the temperature of the planar optical waveguide component even if it is thin.
Space saving in arrangement can be achieved, and a thin optical waveguide module having an appropriate thickness of 9 mm or less can be provided. In particular, even when the thin optical waveguide module of the present invention is mounted on a mounting bus of a substrate, the space for one slot is sufficient, and the space can be saved.

[Brief description of the drawings]

FIG. 1 is a plan view of a thin optical waveguide module according to the present invention.

FIG. 2 is a front view showing a section of the thin optical waveguide module of FIG. 1;

FIG. 3 is a characteristic diagram showing a relationship between a heat radiation area and a thermal resistance in the thin optical waveguide module.

FIG. 4 is a cross-sectional front view of another embodiment of the thin optical waveguide module of the present invention.

FIG. 5 is a front view showing a cross section of still another embodiment of the thin optical waveguide module of the present invention.

FIG. 6 is a model diagram for explaining a general expression conventionally used for a heat absorption amount and a heat release amount of a temperature control element.

FIG. 7 is a model diagram for explaining an approximate expression for obtaining the maximum value of the heat input amount in the thin optical waveguide module.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thin optical waveguide module 2 planar optical waveguide component 3 optical connector 3 a incident fiber 4 optical connector 4 a emission fiber 5 temperature sensor 6 temperature control element 6 a first surface 6 b second surface 7 package 8 metal base 9 protective case 10 fixing member 11 Rubber boot 12 Cover 20 Optical waveguide module 21 Optical waveguide component 22 Optical connector 22a Incident fiber 23 Optical connector 23a Emitting fiber 24 Heat equalizing plate 25 Temperature sensor 26 Temperature control element 26a First surface 26b Second surface 27 Package 27a Rubber boot 28 Metal base 29 Upper cover 30 Optical waveguide module 31 Optical waveguide component 32 Optical connector 32a Incident fiber 33 Optical connector 33a Emitting fiber 34 Heat equalizing plate 35 Temperature sensor 36 Temperature control element 36a First surface 36b Second surface 37 Package 37a Rubber boot 38 Metal base 39 Top cover LI Heat insulation layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsunetoshi Saito 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Koichi Shintomi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo No. Furukawa Electric Co., Ltd.

Claims (2)

[Claims] At least one of a planar optical waveguide component, a temperature sensor for detecting a temperature of the planar optical waveguide component, and a temperature for controlling the temperature of the planar optical waveguide component, the temperature sensor having first and second surfaces. A thin optical waveguide module in which a control element is housed in a package, wherein the temperature control element has a first surface on an inner surface of the package via a first heat conductive material, and a second surface on the flat surface. The planar optical waveguide component or the planar optical waveguide component is disposed in close contact with the planar optical waveguide component via a second heat conductive material, and is disposed between the planar optical waveguide component and the package in the thickness direction of the package. A thin optical waveguide module, wherein a heat insulating layer is formed. 2. The heat-insulating layer has a thickness of 0.8 mm or more, the package on which the first surface of the temperature control element is disposed in close contact with the package has a thickness of 0.2 mm or more, and the heat-insulating layer and the package have a thickness of 0.2 mm or more. The thin optical waveguide module according to claim 1, wherein the total thickness is 7 mm or less, and the total thickness of the package is 9 mm or less.