JPS63306402A - Method for packaging optical element - Google Patents

Abstract

PURPOSE:To fix a semiconductor optical element to packaging parts without generating a positional deviation by previously setting a substrate to a prescribed temp. and executing a registration stage, then supplying a fixing agent at the time of fixing the packaging parts and the substrate with the fixing agent after mounting the element to the packaging parts. CONSTITUTION:The optical element 4 is mounted on the packaging parts 24 and the packaging parts are superposed on the substrate 1 formed with 1st and 2nd conductor patterns 21, 22 insulated electrically from each other and the registration of light guides 2 and the element 4 is executed in such a manner that the element 4 comes into contact with the 1st pattern 21 and the packaging parts 24 come into contact with the 2nd pattern 22. The packaging parts 24 and the substrate 1 are fixed by using the fixing agent 25. The substrate 1, the elements 4 and the parts 24 are heated up to the temp. at which the patterns 21, 22 are melted to electrically connect the pattern 21 and the element 4 and to electrically connect the pattern 22 and the parts 24. The element 4 is thereby precisely registered to the end parts of the light guides and fixed onto the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for mounting optical elements, which is important when manufacturing a hybrid optical integrated circuit.

[Conventional technology]

In order to reduce the size, reliability, and cost of various optical circuits required in the fields of optical communications and optical information processing, we are developing hybrid optical integrated circuits that combine optical waveguides formed on a substrate with various elements. It is hoped that this will be realized.

Figure 6 shows a prototype of this type of hybrid optical integrated circuit, S,! ! This is an example of integrating a quartz light multi-mode optical waveguide formed on a base plate and a semiconductor laser (1).
1. Terui, Y., YaIlada, H. Ka.
wachiand H, ni obayashi “Hy
bridge Integration of aLase
r Diode and Ilight-silica
HultimodcOptical Channel
Waveguide on 5illion''.

Nectron, Lett,, Vo121. DO64
6-648, 1985). In Figure 6, 1 is S = substrate,
2 is an optical waveguide, which includes a core FfI2a and a buffer FJ2.
It has a 3F and 4m structure with a cladding layer 2c and a cladding layer 2c. 3 is a laser guide, 4 is a semiconductor radar, and 4a is its active layer. 6 is a power supply wire, and 7 is a W film. The semiconductor laser 4 is pressed against the laser guide 3 and positioned at an appropriate position relative to the optical waveguide 2. The allowable positional deviation between the laser and the waveguide is as small as ±2 to 3 tas in a multimode system and ±0.5 to 1.0 in a single mode system, and extremely high positioning accuracy is required.

Precise alignment as described above is performed, for example, as shown in FIG. In the figure, 8 is a manipulator, 9 is a stage, and 10 is a fiber.

Regarding the height direction, since the height of the center of the core 1I2a of the optical waveguide 2 is designed and manufactured in advance to match the height of the active layer 4a of the semiconductor laser 4, the semiconductor laser 4 is placed on the substrate 1. Alignment can be achieved just by installing it. On the other hand, in the lateral direction, the semiconductor laser 4 is held by the manipulator 8 and the position of the semiconductor laser 4 is moved on the substrate 1 while the optical coupling efficiency between the semiconductor laser 4 and the optical waveguide 2 is monitored. This can be achieved by finding the position where maximum efficiency can be obtained (Patent Application 1986-473)
No. 67, Yamada, Kobayashi, Pronation "Hybrid optical integrated circuit assembly device J). In addition, in Fig. 7, stage 9 is
It also serves as a heater for controlling the humidity and temperature of the substrate 1.

[Problem that the invention seeks to solve]

By the way, conventionally, to fix a semiconductor optical device on a substrate,
(D) Thermocompression bonding with a low melting point metal, or (ii) bonding with a fixing agent such as solder or adhesive, is generally used. In the thermocompression bonding method, when fixing the element, the humidity of the substrate is controlled by the low melting point metal. It is necessary to perform MW to a humidity higher than the melting point (for example, 320° C. or higher for Au-3n alloy).If the substrate humidity is raised to higher than the melting point prior to alignment, the above-mentioned lateral alignment will not be possible. This is because once a semiconductor optical device is placed on a substrate, it is fixed in place, making it impossible to move the semiconductor optical device on the substrate and find the position where the coupling efficiency is maximized. Conversely, when the substrate is heated and fixed after alignment, thermal expansion of the manipulator 8 holding the semiconductor optical device or stage 9 on which the substrate is placed may occur during the heating process. Due to thermal expansion, a positional shift occurs between the semiconductor optical device and the optical waveguide.In the device shown in Fig. 7, this positional shift peak was approximately 10 m for a humidity difference of 100°C. It is difficult to fix the element using the crimping method.On the other hand, (U
) When fixing with a fixing agent, it is not possible to supply the fixing agent onto the substrate in advance for the reasons mentioned above. Further, after alignment, a fixing agent cannot be supplied between the substrate and the semiconductor optical device. Therefore, after alignment, a fixing agent must be applied to the side surface of the semiconductor optical device, and if the fixing agent is supplied in this way, there is a risk that the fixing agent will wrap around the active layer surface of the semiconductor optical device or the side surface of the optical waveguide. .

Therefore, the conventional method described above has problems such as difficulty in precisely positioning the semiconductor optical device at the end of the optical waveguide and fixing it on the substrate.

An object of the present invention is to provide a method for mounting an optical device that solves the above problems.

[Means for solving problems]

The present invention includes an optical element mounted on a mounting component, a substrate on which first and second conductive patterns electrically insulated from each other are formed, the optical element is in contact with the first conductive pattern, and the optical element is mounted on the substrate. The mounted component carrying the optical element is stacked so that the component is in contact with the second conductor pattern, the optical waveguide formed on the substrate is aligned with the optical element, and the mounted component and the substrate are aligned. By fixing the substrate, the optical element, and the mounting component using a fixing agent, and increasing the humidity of the substrate, the optical element, and the mounting component to a level that melts the first and second conductive patterns, the first conductive pattern and the optical The device is characterized in that the second conductive pattern and the mounted component are electrically connected to each other.

In the present invention, the mounted component and the board are fixed using a fixing agent, but care is taken so that the part where the fixing agent is used is located away from the optical element, so that the fixing agent does not light up. Care is taken to prevent it from wrapping around the active layer surface of the device.

〔Example〕

[Example 1] FIGS. 1(a) and 1(b) are 16 diagrams explaining the first example of the present invention, in which 1 is a substrate (for example, an SL substrate), 1b is a
2 is a buffer layer, 2 is an optical waveguide (for example, a quartz optical waveguide), 21 is a first conductor pattern, 22 is a second conductor pattern, 23 is a conductor pattern for a chip carrier, 24 is a chip carrier (mounted component), 24a is a chip carrier convex portion. Moreover, 4 is a semiconductor optical device, and each second device such as a semiconductor laser, an optical amplifier, a photodetector, and an optical gate corresponds to this. Further, 25 is a fixing agent.

In this embodiment, an adhesive is used. FIG. 1(a) shows the chip carrier portion, and the semiconductor optical device 4 is fixed on the surface of the chip carrier 24 with the active layer 14a facing upward. A conductive layer 1!26 is formed on the surface of the semiconductor optical device 4. Since the conductive pattern 23 is formed on the surface of the chip carrier 24, the n-electrode of the semiconductor optical device 4 can be taken from the surface of the chip carrier 24.

Further, the height J2 of the chip carrier convex portion 24a is set to be approximately equal to the height J3 of the semiconductor optical device 4. The chip carrier 24 is made of a material with good thermal conductivity, such as Si, in order to serve as a heat sink for the semiconductor optical device 4.
Alternatively, Cu is used. FIG. 1(b) shows the semiconductor optical device 4 mounted on the chip carrier 24 in an upside-down configuration with the active J44a facing downward. For mounting, after aligning the semiconductor optical device 4 to the optimum position using a device similar to that shown in FIG. 7, the fixing agent 25 is supplied around the chip carrier convex portion 24a and cured. It was fixed by

At this time, an adhesive that hardens at a humidity lower than the melting point of the metal used for the conductor patterns 21 and 22 is used as the fixing agent. Note that it is desirable that the difference between the curing humidity of the adhesive and the melting point of the conductive pattern metal be small. Further, the amount of adhesive dripped 1 is set to be sufficient to fix the chip carrier convex portion 24a and to prevent it from flowing around to the semiconductor optical device 4. Prior to alignment, the humidity of the substrate is set to be higher than the curing humidity of the adhesive and lower than the melting point of the conductor patterns 21 and 22,
In this state, the optical waveguide 2 and the semiconductor optical device 4 are precisely aligned, and by continuing to supply adhesive, the semiconductor optical device 4 can be fixed on the substrate 1 without any positional shift. This is because the series of steps of alignment → adhesive supply → fixing can be performed without changing the substrate humidity, which prevents misalignment of the semiconductor optical device due to thermal expansion of the assembly jig due to changes in Iff. That's because there isn't. As a result, the pin'R pole (conductive w
! 26) and the conductor pattern 21, the pHg electrode can be taken out from the first conductor pattern 21.

Similarly, the nll electrode passes through the conductor pattern 23 formed on the surface of the chip carrier 24, and passes through the chip carrier convex portion 24.
It is connected to the second conductor pattern 22 through a. After the adhesive has sufficiently hardened, the substrate humidity is increased and the conductor pattern 21
．． The temperature is raised above the melting point of 22. As a result, the p-side electrode of the semiconductor optical device, the conductor pattern 21 and the chip carrier convex portion 2
4a (that is, the n1llllffi pole) and the conductor pattern 22 are electrically connected. Note that since the chip carrier 24 is fixed by the fixing agent 25, the positional shift of the semiconductor optical device 4 during this temperature rising process can be suppressed.

In this way, according to this embodiment, the semiconductor optical device can be fixed to the end of the optical waveguide in a precisely aligned state. Moreover, since the electrical wiring is completed at the same time, a wire bonding process is not necessary.

[Example 2] FIG. 2 is a diagram showing a second example of the present invention, in which a liquid reservoir 3 surrounded by a convex pattern formed at the same time as the optical waveguide 2 is shown.
A fixation method using 0 is shown. In FIG. 2(a), a liquid reservoir 30 is formed near the # section of the waveguide 2, and conductor patterns 21 and 22 are formed on both sides of this reservoir. FIG. 2(b) shows a fixing method using this liquid reservoir 30.

After the semiconductor element 4 was mounted on the chip carrier 24'' as shown in FIG. 1(a), it was aligned with the waveguide 2 in the upside-down state as in Example 1. Next, the fixing agent 25 is poured into the liquid reservoir 30 to fix the chip carrier 24. This method is an easier fixing method than Example 1 because there is no fear that the fixing agent 25 will flow toward the semiconductor element 4 side.

[Example 3 FIG. 3 is a diagram illustrating a third embodiment of the present invention.

As shown in FIG. 3(a), a liquid reservoir 30 was formed near the waveguide 2, and a first conductor pattern 21 was formed between the waveguide 2 and the liquid reservoir 30. The second conductor pattern 22 is the liquid reservoir 3
It is formed on 0.

The semiconductor optical device 4 is mounted on a chip carrier 2 shown in FIG. 3(b).
4 to be installed on top. At this time, the relationship between the height J+ of the liquid reservoir 30, the height J2 of the convex portion 24a of the chip carrier 24, and the height J3 of the semiconductor optical device 4 is J3ヾJI+42 (FIG. 3C). . Therefore, the chip carrier can be fixed by mounting the semiconductor optical device 4 upside down on the substrate and supplying a fixing agent into the liquid reservoir 30 after alignment. After fixing, the substrate is MALed and electrical connections are completed in the same manner as in Example 1.

[Example 4] FIG. 4 shows an example in which the liquid reservoir 30 is formed by carving the buffer layer 1b into a concave shape. Similar to the embodiment of FIG.
The second conductor pattern 22 is formed on the liquid reservoir 30. The height J2 of the convex portion 24a of the chip carrier 24 and the height J3 of the semiconductor optical device 4 are set to be approximately equal. After alignment in the same manner as in Example 1, the liquid reservoir 3
The chip carrier 24 can be fixed by supplying a fixing agent 25 into the container.

[Embodiment 5] FIG. 5 is a diagram showing a fifth embodiment of the present invention. In the figure, the optical waveguide 2 is a quartz-based optical waveguide, and is formed on the St substrate 1 having irregularities. A buffer layer 1b is formed in the recess 31 of the SL substrate 1, and an optical waveguide 2 is formed thereon. Si is exposed on the surface of the SL substrate convex portion 32 (Japanese Patent Application No. 61-27705)
No. 8, Yamada, Yonai, Kobayashi "Hybrid Optical Integrated Circuit J)
a The first conductor pattern 21 is a silica-based optical waveguide buffer 1
1b, and a second conductor pattern 22
is patterned on the surface of the SL substrate convex portion 32.

A liquid reservoir 30 similar to that in the second embodiment is formed between the first conductor pattern 21 and the second conductor pattern 22. After aligning the semiconductor element 4 mounted on the chip carrier 24 upside down, the fixing agent 2 is poured into the liquid reservoir 30.
5, the chip carrier 24 can be fixed on the substrate. In this embodiment, as in the above-described embodiments, the semiconductor optical device 4 can be fixed to the end of the optical waveguide without causing any positional shift. In addition, in this example,
Convex portion 24a of chip carrier 24 that also serves as a heat sink
is in contact with the surface of the SL substrate via the conductor pattern 22.

Therefore, the heat generated in the semiconductor optical device 4 escapes to the SL substrate 1 via the chip carrier 24, so that the cooling effect is excellent.

In the above embodiments, the semiconductor optical device is mounted upside down on the substrate, but the present invention can also be applied to the case where the semiconductor optical device is mounted upside down.

〔Effect of the invention〕

As explained above, in the present invention, when integrating an optical waveguide and an optical semiconductor optical device that require precise alignment, the semiconductor optical device is mounted on a mounting component, and then the mounting component and the substrate are fixed with a fixing agent. As a result, by setting the substrate at a predetermined humidity in advance and performing the positioning process, and then supplying the fixing agent, it is possible to fix the substrate without causing any displacement. Further, in the present invention, since the part where the fixing agent is used is located at a position separated from the optical element, it is possible to prevent the fixing agent from getting around to the active surface of the optical element. Further, in the present invention, one electrode of the semiconductor optical device is brought into contact with one of the two conductor patterns formed on the substrate, and the booster electrode is brought into contact with the other conductor pattern through the mounting component. As a result,
This method has the advantage of simplifying the process because electrical wiring can be established by simply mounting the semiconductor optical device on the substrate without requiring a wire bonding process.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are explanatory diagrams of the first embodiment of the present invention,
FIGS. 2(a) and (b) are explanatory views of the second embodiment of the present invention with the liquid reservoir on the right, and FIGS. 3(a) to 3(C) are explanatory diagrams of the third embodiment of the present invention.
FIGS. 4(a) and 4(-t) are explanatory diagrams of the fourth embodiment of the present invention, and FIG. 5 is an explanatory diagram of the 15th embodiment of the present invention. FIG. 6 is an explanatory diagram showing a conventional method for mounting a semiconductor optical device, and FIG. 7 is a diagram explaining a mounting process of a semiconductor optical device. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Optical waveguide, 4... Optical device (semiconductor optical device), 21... First η-body pattern, 22...
- Second conductor pattern, 24... Mounted component (chip carrier), 25... Fixing agent.

Claims (1)

[Claims] An optical element is mounted on a mounted component, on a substrate on which first and second conductive patterns electrically insulated from each other are formed, the optical element is in contact with the first conductive pattern, and the mounted component is in contact with the first conductive pattern. The mounted component carrying the optical element is stacked so as to be in contact with the conductor pattern No. 2, the optical waveguide formed on the substrate and the optical element are aligned, and the mounted component and the substrate are bonded with a fixing agent. By fixing the substrate, the optical element, and the mounted component to a humidity that melts the first and second conductive patterns, the first conductive pattern and the optical element are connected to each other by electricity. and the second
A method for mounting an optical device, comprising electrically connecting a conductor pattern and the mounted component.