JPH09211266A - Semiconductor device and optical communication module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the long-term in-casing temp. of a package formed by using resin by providing the internal space or the inside of the sealing resin in the package with a heating element and allowing this heating element to generate heat, thereby maintaining the temp. of the internal space or the sealing resin higher than the temp. of the atmosphere in which the package is placed. SOLUTION: A substrate 1 consists of Si or glass and its front surface is provided with wirings for transmitting electric power and electric signals to a semiconductor laser element 4, a photodetecting diode 5, a driving IC 6 and the heating element 7. The heating element 7 is energized to generate heat, by which the relative temp. in the internal space 13 is lowered and dew condensation is prevented. The evaporation of the moisture included in the resin 3 and adhesive 12 is accelerated and the moisture is discharged as steam to the outside of a model by elevating the temp. of the resin 3 and the adhesive 12 higher than the atmosphere in which the module is placed by the heat generation. The heating element is continuously driven to prevent the elevation of the relative temp. in the internal space by starting the driving of the heating element simultaneously with the operation start of the module.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small package product having a space inside such as an optical communication module, a ceramic package IC or a plastic package I.
For resin-sealed circuit parts such as C and COB substrates,
The present invention relates to a device for optimizing moisture or water in an internal space or a sealing resin.

[0002]

2. Description of the Related Art A conventional optical communication module is provided with a light emitting element such as a semiconductor laser chip or a light receiving element such as a photodiode inside its metal housing, and is used for optical coupling with an optical fiber, an optical waveguide or a lens system. For this reason, there is a space filled with gas, and this internal space is sealed by a method such as welding in order to prevent the ingress of corrosive gas and moisture and prevent the deterioration of the element. In recent years, in order to reduce the cost of optical communication modules, not only a welded structure made of only metal, but a structure in which members such as metal, glass, silicon, ceramics and resin are adhered by resin, or as shown in Japanese Patent Laid-Open No. 304405/1989. They are trying to replace the structure in which optical components are directly sealed with resin. However, any resin has a certain degree of moisture permeability, and suppressing the entry of moisture or water into the housing is an important issue in protecting the internal elements and ensuring the life. There is. This moisture or moisture infiltration problem is caused by the plastic package IC
The same applies to resin-sealed parts such as and COB substrates. The conventional technique is to reduce the internal humidity by using a resin having a low moisture permeability or by putting an adsorbent that adsorbs moisture inside, as shown in the manual of the moisture absorbent SD1000 of Techno Alpha Co., Ltd. There is a method to keep it constant, but the capacity of the adsorbent is limited, and even if the moisture permeability of the sealing resin is low, moisture will infiltrate in the long term, maintain an appropriate humidity, and prevent condensation inside. There was a problem that it could not be prevented.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to the problem of long-term optimization of the humidity inside the housing in a resin-using package, to optimize the humidity inside the housing for a long term.

[0004]

In the present invention, in order to solve the above problems, a heating element is provided in the internal space of the package or in the sealing resin. By causing this heating element to generate heat, the temperature of the internal space or the sealing resin becomes higher than the atmosphere in which the package is placed, and the water present in the atmosphere as water vapor is condensed or condensed in the internal space or the sealing resin. This prevents the infiltration of water. Further, the water already present in the internal space or the sealing resin is easily vaporized by heating, and the vapor generated by the vaporization goes out of the package or the sealing resin to lower the relative humidity inside. It is also possible to prevent condensation inside.

Further, by providing an internal humidity sensor, measuring the internal humidity, and driving the heating element based on the humidity data, the heating element can be driven for an appropriate period of time. The power required for driving can be saved. Further, by incorporating the temperature sensor, taking in the internal temperature information, and correcting the humidity data, the humidity data can be obtained more accurately, and as a result, the heating element can be driven more appropriately.

If the heat generation amount of this heating element is sufficient, the internal electric circuit or integrated circuit, or the light emitting element or the light receiving element itself can be used as the heating element. In that case, a cooling mechanism should be provided outside the package, and the cooling mechanism outside the package is controlled based on a signal output from the temperature sensor or the humidity sensor inside the package to the outside. Thereby, the package temperature is controlled, and moisture is released from the package.

[0007]

1 is a sectional view of an example of a semiconductor device with a heating element according to the present invention. In this embodiment, an example is shown in which the optical communication module is provided with a heating element. The substrate 1 is made of Si or glass, and has a semiconductor laser element 4 (hereinafter abbreviated as LD), a light-receiving photodiode 5 (hereinafter abbreviated as PD), a driving IC 6, and a heating element 7 on which power is supplied to the surface. Wiring for transmitting an electric signal is provided, and a part of this wiring is electrically connected to the electric signal terminal 8 to the outside. LD4, PD5, drive I on the substrate 1
The C6 and the heating element 7 are mounted by soldering and are electrically connected to the wiring, and part of them are also wired by the wire bonding 9. Further, the optical fiber 1 is provided in the V groove portion 10 on the substrate 1.
1 is mounted so as to be optically coupled with the LD 4, and outputs an optical signal to the outside. The lid 2 is made of borosilicate glass or Pyrex glass, and is fixed to the substrate 1 by a resin adhesive 12, and a space 13 is formed inside. At the manufacturing stage of the module, the space 13 is filled with dry nitrogen gas. The substrate 1 and the lid 2 are entirely sealed with resin 3. The resin 3 and the adhesive 12 have moisture permeability, and moisture will penetrate into the internal space 13 in the long term.
Moisture that has entered the internal space 13 is LD4, PD inside.
5, the driving IC 6 is deteriorated, the internal wiring is corroded, or the LD 4, PD 5, and the end surface of the optical fiber 11 are condensed to adversely affect the optical coupling. Here, by energizing the heating element 7 to generate heat, the relative humidity of the internal space 13 decreases, and dew condensation can be prevented. Further, the temperature of the resin 3 and the adhesive 12 is raised from the atmosphere in which the module is placed by the heat generation, thereby promoting the vaporization of the water contained in the resin 3 and the adhesive 12, and the water vapor to the outside of the module. Can be discharged as. It is also possible to prevent the relative humidity in the internal space from rising by starting the driving of the heating element at the same time as the operation of the module and continuously driving it.

FIG. 2 is a sectional view of another example of a semiconductor device with a heating element according to the present invention. The substrate 1 is made of Si or glass, and wiring for transmitting electric power and electric signals to the semiconductor laser element 4, the light receiving photodiode 5, the driving IC 6, and the heating element 7 is provided on the surface. Is electrically connected to the electric signal terminal 8 to the outside. The LD 4, the PD 5, the driving IC 6, and the heating element 7 are mounted on the substrate 1 by soldering and are electrically connected to the wiring, and a part of them are also wired by the wire bonding 9. Further, an optical fiber 11 is mounted in the V groove portion 10 on the substrate 1 so as to be optically coupled with the LD 4, and outputs an optical signal to the outside. LD4, PD5, driving IC6 and heating element 7 on the substrate 1 are LD
Resin 1 that transmits light having an oscillation wavelength of 4 and a light receiving wavelength of PD5
It is sealed by 4, and the optical coupling between the optical fiber 11 and the LD 4 is also performed through the resin 14. Further, the substrate 1 and the resin 14 do not transmit the light of the light receiving wavelength of the PD 5 in order to prevent ambient light or protect the resin inside.
It is sealed by 5. In the present embodiment, the heating value of the heating element 7 is sufficient to make the temperature of the resin 14 and the resin 15 higher than the atmospheric temperature outside the module, and the heating of the heating element 7 causes the temperature of the resin 14 and the resin 15 to rise. Moisture that has risen above the atmospheric temperature and has penetrated into the resin 14 and the resin 15 is promoted to vaporize and is released into the atmosphere as water vapor. Further, since the temperatures of the resin 14 and the resin 15 are higher than the atmospheric temperature, dew condensation on the surface of the resin 15 is prevented.

FIG. 3 is a sectional view of an example of an apparatus having a humidity sensor and a heating element according to the present invention therein. The substrate 1 is made of Si or glass and has LD4, PD on the surface.
5, a wiring for transmitting electric power and electric signals to the driving IC 6, the heating element 7, the humidity sensor 16, and the heating element driving circuit 17 is provided, and a part of this wiring is conducted to the electric signal terminal 8 to the outside. doing. The LD 4, PD 5, driving IC 6, heating element 7, humidity sensor 16, and heating element driving circuit 17 are mounted on the substrate 1 by soldering and are electrically connected to the wiring.
A part is also wired by wire bonding 9. Further, the optical fiber 11 is placed in the V groove 10 on the substrate 1
It is mounted so as to be optically coupled with D4, and outputs an optical signal to the outside. The lid 2 is made of borosilicate glass or Pyrex glass, and is fixed to the substrate 1 by a resin adhesive 12, and a space 13 is formed inside. At the manufacturing stage of the module, the space 13 is filled with dry nitrogen gas. The humidity sensor 16 measures humidity by a change in electric resistance due to moisture absorption of resin between the electrodes.
When the humidity of 3 increases, the resin between the electrodes of the humidity sensor 16 also absorbs moisture, and the electrical resistance between the electrodes decreases. Humidity sensor 16
The heating element drive circuit 17 which is conducted to detect the decrease in the electric resistance, and drives the heating element 7 when the resistance decreases below a preset value. By causing the heating element 7 to generate heat, the relative humidity of the internal space 13 decreases, and dew condensation can be prevented. Further, the heat generation raises the temperature of the adhesive 12 from the atmosphere in which the module is placed, thereby promoting vaporization of water contained in the adhesive 12 and discharging the water to the outside of the module as water vapor.

FIG. 4 is an explanatory view of a substrate portion of a module which is another example of the apparatus having a humidity sensor and a heating element according to the present invention, and FIG. 5 is a sectional view of the module of FIG. Substrate 1 is made of Si and has LD on its surface.
4, PD 5, driving IC 6, heating element 7, and heating element driving circuit 17 are provided with wirings for transmitting electric power and electric signals, and these wirings are electrically connected to electric signal terminals 8 to the outside. In this example, the electrode 18 is a part of the wiring on the substrate 1. As shown in FIG. 5, LD4 and PD on the substrate 1
5, by covering the electrodes 18 together with the driving IC 6, the heating element 7, the heating element driving circuit 17, and the end face of the optical fiber 11 with the resin 14, the resin enters the space between the electrodes 18, which is similar to the humidity sensor 16 in FIG. The structure can be realized and operates as the humidity sensor 19. The heating element drive circuit 17 detects the change in the electrostatic capacitance between the electrodes 18 due to the moisture absorption of the resin 14, drives the heating element 7, raises the temperature of the resin 14, and disperses water as water vapor.

FIG. 6 is a cross-sectional view of an example of an apparatus having a temperature sensor, a humidity sensor and a heating element according to the present invention. Substrate 1
Is made of Si or glass, and the surface is LD
4, PD 5, driving IC 6, heating element 7, humidity sensor 1
6, wiring for transmitting electric power and electric signals to the temperature sensor 19 and the heating element drive circuit 17 is provided, and a part of this wiring is electrically connected to the electric signal terminal 8 to the outside. The LD 4, the PD 5, the driving IC 6, the heating element 7, the humidity sensor 16, the temperature sensor 19, and the heating element driving circuit 17 are mounted on the substrate 1 by soldering and are electrically connected to the wiring. Is also wired. Further, an optical fiber 11 is mounted in the V groove portion 10 on the substrate 1 so as to be optically coupled with the LD 4, and outputs an optical signal to the outside. The lid 2 is borosilicate glass or Pyrex glass,
It is fixed to the substrate 1 by a resin adhesive 12, and a space 13 is formed inside. At the manufacturing stage of the module, the space 13 is filled with dry nitrogen gas. The humidity sensor 16 measures humidity by a change in electric resistance due to moisture absorption of the resin between the electrodes, and when the humidity of the internal space 13 rises, the resin between the electrodes of the humidity sensor 16 also absorbs moisture.
The electrical resistance between the electrodes is reduced. However, since the internal resistance of the electric circuit generally increases as the temperature rises, it is not possible to obtain accurate humidity information of the internal space 13 simply by measuring the electric resistance of the humidity sensor 16. By correcting the humidity information obtained from the electric resistance value of the humidity sensor 16 based on the temperature information of the internal space 13 obtained from the temperature sensor 19, accurate humidity information can be obtained, and the heating element can be set at a more appropriate time. By driving, the power consumption can be reduced. Further, by using the temperature information itself as a criterion for driving the heating element 7, it is useful to prevent overheating of the heating element 7 and to stabilize the environment inside the package.

FIG. 7 is a sectional view of an example of a semiconductor device with a heating element according to the present invention. The IC chip 20 has an electric resistance portion 24 serving as a heating element inside, and is mounted on a lead-attached frame substrate 21.
1 is an electric terminal portion 22 for inputting / outputting electric signals to / from the outside
Accompanied by. The IC chip 20 and the frame substrate with lead 21 are sealed with resin 23 except for the electric terminal portion 22. In case of general plastic package IC,
This resin is a black epoxy resin and is resin-sealed by a method called transfer molding. This resin 23 also has moisture permeability, and there are problems such as corrosion of wiring due to water that has penetrated inside or peeling of the resin from the frame substrate with leads. By using the IC chip 20 provided with the heating element 24, the temperature of the resin 23 is raised, the moisture in the interior is discharged as water vapor, the dew condensation on the surface of the resin 23 is prevented, and the infiltration of the moisture into the interior is suppressed. .

FIG. 8 is a sectional view of an example of a semiconductor device in which the internal component of the present invention also serves as a heating element. The substrate 1 is made of Si or glass, and the surface thereof is provided with wiring for transmitting electric power and electric signals to the semiconductor laser element 4, the light receiving photodiode 5, the driving IC 6, and the cooling device driving circuit 25. A part of this wiring is electrically connected to the electric signal terminal 8 to the outside. LD4, PD5, on the substrate 1
The drive IC 6 and the cooling device drive circuit 25 are mounted by soldering and are electrically connected to the wiring, and a part of them are also wired by the wire bonding 9. Further, an optical fiber 11 is mounted in the V groove portion 10 on the substrate 1 so as to be optically coupled with the LD 4, and outputs an optical signal to the outside. LD on substrate 1
4, PD5, driving IC6 is the oscillation wavelength of LD4 and PD5
The resin 14 is sealed by the resin 14 that transmits the light of the received light wavelength, and the optical coupling between the optical fiber 11 and the LD 4 is also performed through the resin 14. Further, the substrate 1 and the resin 14 are sealed with a resin 15 that does not transmit light of the wavelength received by the PD 5 in order to prevent ambient light or to protect the resin inside. Further, a cooling device 26 using a Peltier element for cooling the module is provided. In this embodiment, the amount of heat generated from the LD 4, PD 5, driving IC 6, cooling device driving circuit 25 and wiring is sufficient to make the temperature of the resin 14 and the resin 15 higher than the atmospheric temperature outside the module. The heat generated from the LD4, PD5, the driving IC6, the cooling device driving circuit 25, and the wiring is generated by the internal resistance or L
Although it depends on the heat generated by the laser beam oscillated by D4, etc.
It is also possible to form an electric resistance portion serving as a heating element on 6 beforehand. LD4, PD during normal operation
5, the temperature of the resin 14 and the resin 15 rises above the atmospheric temperature due to the heat generated from the driving IC 6, the cooling device driving circuit 25, and the wiring, and the moisture that has infiltrated into the resin 14 and the resin 15 is promoted to vaporize and vapor Is released into the atmosphere. Further, since the temperatures of the resin 14 and the resin 15 are higher than the atmospheric temperature, dew condensation on the surface of the resin 15 is prevented. The temperature sensor 19 measures the temperature inside the module, controls the cooling device 26 through the cooling device drive circuit 25, and cools the cooling device 26 when the module temperature rises above the set temperature.
Drive to maintain the module temperature at an appropriate value and prevent module failure due to abnormal overheating.

The controllable cooling device 26 is not limited to one using a Peltier element, but one having an electric fan mounted on a module, or a device housing a module with cooling fins mounted on the module. A method of cooling with an electric fan provided can be considered.

[0015]

According to the present invention, by heating the internal space in the package or the sealing resin, the temperature of the internal space or the sealing resin becomes higher than that of the atmosphere in which the package is placed, and the atmosphere contains water vapor. Moisture present does not condense or condense in the internal space or the sealing resin, and infiltration of moisture can be suppressed. Further, the water already present in the internal space or the sealing resin is easily vaporized by heating, and the vapor generated by the vaporization goes out of the package or the sealing resin to lower the relative humidity inside. It is also possible to prevent condensation inside.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of a semiconductor device with a heating element according to the present invention.

FIG. 2 is a sectional view of an example of a semiconductor device with a heating element according to the present invention.

FIG. 3 is a cross-sectional view of an example of a semiconductor device with a humidity sensor and a heating element according to the present invention.

FIG. 4 is an explanatory view of a substrate portion of an example of a semiconductor device with a humidity sensor and a heating element of the present invention.

FIG. 5 is a cross-sectional view of an example of a semiconductor device with a humidity sensor and a heating element according to the present invention.

FIG. 6 is a cross-sectional view of an example of a device having a temperature sensor, a humidity sensor, and a heating element according to the present invention therein.

FIG. 7 is a sectional view of an example of a semiconductor device with a heating element according to the present invention.

FIG. 8 is a cross-sectional view of an example of a semiconductor device in which an internal component of the present invention also serves as a heating element.

[Explanation of symbols]

1 ... Substrate, 2 ... Lid, 3 ... Resin, 4 ... Semiconductor laser element,
5 ... Photodiode for light reception, 6 ... Driving IC, 7 ... Heating element, 8 ... Electrical signal terminal, 9 ... Wire bonding, 1
0 ... V groove, 11 ... Optical fiber, 12 ... Adhesive, 13 ...
Interior space.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Takahashi 5-20-1, Kamisuihonmachi, Kodaira-shi, Tokyo Hitachi, Ltd. Semiconductor Division

Claims (15)

[Claims] 1. A housing formed of a member made of metal, glass, ceramic, zirconia, alumina, silicon or resin into a shape having an internal space isolated from the outside air by welding, soldering, bonding, hermetic sealing or integral molding. And an electric circuit, an integrated circuit, a light emitting element, a light receiving element, an optical lens, an optical switch, an optical filter, an optical filter, an optical fiber, or a combination thereof in the internal space, the electric circuit, the integrated circuit, or the light emitting element. Alternatively, an electric terminal for inputting / outputting electric power or an electric signal to / from the light receiving element, the optical lens, the optical switch, the optical waveguide, the optical filter, the optical fiber alone or a combination thereof, and the electric circuit or the A second heating element or a third heating element included in the integrated circuit, the light emitting element, or the light receiving element, or the electric circuit, the integrated circuit, the light emitting element, or the light receiving element. Optical communication module. 2. The unit according to claim 1, wherein the internal space is filled with a resin, and the electric circuit, integrated circuit, light emitting element, light receiving element, optical lens, optical switch, optical waveguide, optical filter, or optical fiber is used. Alternatively, a heating element that also serves as the electric circuit, integrated circuit, light emitting element, or light receiving element or a combination thereof, or a heating element included in the electric circuit, integrated circuit, light emitting element, or light receiving element, or the electric circuit, integrated circuit, or light emitting element An optical communication module in which a heating element separate from an element or a light receiving element is sealed with the resin. 3. An electric circuit, an integrated circuit, a light emitting element, a light receiving element, an optical lens, an optical switch, an optical waveguide, an optical filter, an optical fiber, or a combination thereof on a substrate, and the electric circuit, the integrated circuit, or the light emitting element. An electric circuit or an integrated circuit having an electric terminal for inputting / outputting electric power or an electric signal to / from an element, a light receiving element, an optical lens, an optical switch, an optical waveguide, an optical filter, an optical fiber or a combination of these Heat that also serves as the electric circuit, integrated circuit, light emitting element, or light receiving element in a resin in which a circuit, a light emitting element, a light receiving element, an optical lens, an optical switch, an optical waveguide, an optical filter, an optical fiber, or a combination thereof is sealed. Body or A heating element included in the electric circuit or the integrated circuit, the light emitting element or the light receiving element or a heating element separate from the electric circuit or the integrated circuit, the light emitting element or the light receiving element, and by heating the heating element, An optical communication module characterized by optimizing the water content in the sealing resin. 4. The humidity according to claim 1, 2 or 3, wherein the internal space or the sealing resin has a humidity sensor whose electric resistance, electrostatic capacity or electromotive force changes depending on humidity. An optical communication module that causes the heating element to generate heat according to humidity information in the internal space or the sealing resin obtained from a sensor. 5. The humidity sensor according to claim 4, wherein the humidity sensor electrically detects that the electric resistance, the electrostatic capacitance, or the electromotive force changes depending on the humidity, and it is determined that the humidity exceeds a preset value. In this case, an optical communication module internally equipped with an electric circuit that outputs a signal that causes the heating element to generate heat. 6. The temperature information obtained by the temperature sensor according to claim 4 or 5, further comprising a temperature sensor whose electric resistance, electrostatic capacity, or electromotive force changes with temperature in the internal space or the sealing resin. An optical communication module that corrects the humidity information obtained from the humidity sensor and controls the heating element according to the corrected humidity information and temperature information. 7. The electric resistance, the electrostatic capacity, or the electromotive force according to claim 1 or claim 2, claim 3 or claim 4, or claim 5 depending on the temperature in the internal space or in the sealing resin. An optical communication module comprising a changing temperature sensor, and controlling the heating element according to temperature information obtained by the temperature sensor. 8. The electrical resistance according to claim 1, 1 or 2 or 3 or 4 or 5 or 6 or 7 depending on temperature in the internal space or in the sealing resin. Alternatively, an optical communication module including a temperature sensor whose capacitance or electromotive force changes and which controls a cooling device for cooling the optical communication module based on temperature information obtained by the temperature sensor. 9. A semiconductor device having a metal lead frame and a semiconductor element including an electric circuit or an integrated circuit, which is covered with resin except for an electric signal terminal portion, or a heating element which also functions as the semiconductor element or the semiconductor. Having a heating element included in the element or a heating element separate from the semiconductor element, by heating the heating element, the relative humidity near the semiconductor element is optimized, or dew condensation in the semiconductor element or the lead frame. A semiconductor device characterized by preventing the following. 10. A semiconductor element having an electric circuit or an integrated circuit mounted on a substrate having electric wiring and covered with a resin, the heating element also serving as the semiconductor element, the heating element included in the semiconductor element, or A semiconductor device comprising a heating element separate from the semiconductor element, and by heating the heating element, the relative humidity near the semiconductor element is optimized or dew condensation on the semiconductor element is prevented. 11. The internal space or sealing resin according to claim 9, further comprising a humidity sensor whose electric resistance, electrostatic capacity, or electromotive force changes depending on humidity, the internal space being obtained from the humidity sensor. A semiconductor device for optimizing relative humidity in the internal space or moisture in the sealing resin or preventing dew condensation in the semiconductor element by causing the heating element to generate heat in accordance with humidity information in the space or the sealing resin. 12. The humidity sensor according to claim 11, which electrically detects that the electric resistance, the electrostatic capacitance, or the electromotive force is changed by the humidity, and it is determined that the humidity exceeds a preset value. In this case, a semiconductor device internally provided with an electric circuit that outputs a signal that causes the heating element to generate heat. 13. The method according to claim 11, wherein
The internal space or the sealing resin is provided with a temperature sensor whose electric resistance, electrostatic capacity, or electromotive force changes according to temperature, and the temperature information obtained by the temperature sensor corrects the humidity information obtained by the humidity sensor, A semiconductor device that controls a heating element according to the obtained humidity information and temperature information. 14. The temperature sensor according to claim 9 or 10, wherein the internal space or the sealing resin is provided with a temperature sensor whose electric resistance, electrostatic capacity or electromotive force changes depending on temperature. A semiconductor device for controlling the heating element according to temperature information provided. 15. Claim 9 or claim 10 or claim 11 or claim 12 or claim 13 or claim 1.
4, a temperature sensor whose electric resistance, electrostatic capacitance, or electromotive force changes with temperature in the internal space or in the sealing resin, and the semiconductor device is configured based on temperature information obtained by the temperature sensor. A semiconductor device for controlling a cooling device for cooling.