JP3277646B2 - Method for manufacturing optical semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a light emitting device and a light receiving device for optical communication using an optical semiconductor chip, and more particularly to a method for hermetically sealing an optical semiconductor chip in an optical semiconductor device.

[0002]

2. Description of the Related Art FIG. 7 is an explanatory view of a conventional example. In the figure, 2 is an optical semiconductor chip, 3 is an electrode pattern, 6 is an active part, 7 is an active part electrode pattern, 8 is a solder bump, 9 is a lens, 10 is a cap, 14 is an optical fiber, 15 is light, and 17 is light. Extraction electrode, 18 is a wire, 25 is a block, 26 is a lead wire,
27 is an insulator and 28 is a window.

Conventionally, as shown in FIG.
After bonding the optical semiconductor chip 2 to the block 25 provided with the electrode pattern 3 and the like, the cap 25 having a transparent window 28 through which the light 15 from the optical fiber 14 is transmitted is welded to the block 25 for hermetic sealing. Was.

[0004]

However, in such a method, it is necessary to bond the chip-shaped window 28 to the cap 10, and at this time, the steps of forming, metalizing, and bonding the window 28 are required. . Therefore, since these steps are performed one by one for each optical semiconductor chip 2, it is troublesome, productivity is low, and the yield is low.

Further, it is necessary to increase the strength of the window
Since it is necessary to match the thermal expansion coefficient of the cap 28 with the cap 10, an expensive material such as sapphire is used for the material of the window 27, and an expensive and poorly workable material such as Kovar is also used for the cap 10. Was used.

For this reason, there has been a problem that the cost of the material parts increases. Furthermore, in the conventional method, since both the bonding of the optical semiconductor chip 2 and the hermetic sealing of the cap 10 are performed one by one, there is a limit in mass productivity.

The present invention has been made in view of the above problems, and provides a method of manufacturing an optical semiconductor device in which a large number of optical semiconductor chips are hermetically sealed at the same time and the process is shortened. It is intended to be.

[0008]

FIG. 1 is an explanatory view of the principle of the present invention, and FIG. 2 is an explanatory view of a first embodiment of the present invention. In the figure, 1 is a transparent substrate, 2 is an optical semiconductor chip, 3 is an electrode pattern, 4 is a coating, 5 is an insulating hermetic ring, 6 is an active portion, 7 is an active portion electrode pattern, 8 is a solder bump, 9 is a lens. , 10 is a cap, 11 is a cap solder bump, 12
Is a convex, 13 is a chip substrate, 14 is an optical fiber, 15 is light, 16
Is an optical fiber device, 17 is an extraction electrode, and 18 is a wire.

In order to solve the above problem, a plurality of optical semiconductor chips 2 are two-dimensionally mounted on a single wafer-shaped transparent substrate 1 by the method of the present invention, and a plurality of optical semiconductor chips 2 are also mounted. After the cap is soldered by the method of the present invention and the optical semiconductor chips are simultaneously hermetically sealed, the cap and the transparent substrate are cut to obtain an optical semiconductor device.

That is, as shown in FIG. 1 (a), an object of the present invention is to form a plurality of electrode patterns 3 having solder wettability on a transparent substrate 1, Forming an insulating airtight ring 5 having a coated film 4 having a coating thereon, and applying the solder bumps 8 of the optical semiconductor chip 2 having a plurality of solder bumps 8 and a convex lens 9 on the back surface to the electrode pattern. 2 and a step of soldering the cap solder bumps of the cap 10 having the cap solder bumps 11 on the lower surface of the insulating airtight ring 5.
Soldering the optical semiconductor chip 2 to hermetically seal the optical semiconductor chip 2; and, as shown in FIG.
And a step of separating the transparent substrate 1 into a chip substrate 13 including the individual optical semiconductor chips 2, as shown in FIG. 2 (a). A chip 2 is soldered on the transparent substrate 1 two-dimensionally arranged on the transparent substrate 1 as shown in FIG.
As shown in (a), the cap solder bump 11 formed two-dimensionally on the lower surface corresponding to the insulating ring 5.
3 and 6, the optical semiconductor chip 2 is collectively air-tightly sealed, so that the optical fiber 14 is further removed from the optical fiber 14, as shown in the embodiment of FIGS. Achieved by bonding an optical fiber device 16 having light reflecting means for bending the optical axis of the optical fiber 14 to the transparent substrate 1 so that the emitted light 15 enters the lens 9 of the optical semiconductor chip 2. Is done.

[0011]

According to the means of the present invention, a transparent substrate in which a large number of optical semiconductor chips are two-dimensionally arranged and a cap in which a large number of caps are two-dimensionally arranged are collectively air-sealed for each wafer. As a result, the production efficiency is increased and the yield is improved as compared with the conventional case.

In addition, since the metallization, bonding, and wiring of the window material can be collectively processed on a wafer basis, it is suitable for mass production. In addition, since the surface mounting mode is adopted, there is an effect that the bonding can be easily automated using a conventional mounting device for mounting components on a printed circuit board. As a result, cost reduction can be realized.

[0013]

FIG. 1 is an explanatory view of the principle of the present invention, and FIGS. 2 to 6 are explanatory views of some embodiments of the present invention, which are shown in schematic sectional views except for the perspective view of FIG.

In the figure, 1 is a transparent substrate, 2 is an optical semiconductor chip, 3 is an electrode pattern, 4 is a coating, 5 is an insulating airtight ring, 6 is an active portion, 7 is an active portion electrode pattern, 8 is a solder bump, 9 is a lens, 10 is a cap, 11 is a cap solder bump, 12 is a projection, 13 is a chip substrate, 14 is an optical fiber, 15 is light, 16, 16a is an optical fiber device, 17 is an extraction electrode, 18 is a wire, 19 is an optical fiber array, 20 is a photodiode array, 21 is a glass substrate, 22 is an optical waveguide, 23 is a semiconductor laser chip, and 24 is a V-grooved Si substrate.

First, the first embodiment of the present invention will be described with reference to FIGS.
An example will be described. As shown in FIG.
A quartz substrate is used as the transparent substrate 1, and a large number of optical semiconductor chips 2 are mounted on the quartz substrate in a wafer state,
Then, a large number of optical semiconductor chips are hermetically sealed with a cap in a single wafer state.

In the process, an electrode pattern 3 of titanium / gold (Ti / Au) is formed on a quartz substrate 1 by a lift-off method, and then a Si ₃ N ₄ film is formed by a plasma CVD method. The insulating airtight ring 5 is formed.

Next, an optical semiconductor chip composed of a flip chip PIN diode with a monolithic lens is sequentially and two-dimensionally flip-chip bonded onto the quartz substrate 1. This optical semiconductor device also has an active part electrode pattern 7 on the active part 6 on the surface of the optical semiconductor chip 2 as shown in the sectional view of FIG. It has four solder bumps for soldering to a substrate and one lens 9 having a substrate processed into a spherical shape at the center.

Next, the active part electrode pattern 7 and the lead electrode are connected by a gold wire. Thereafter, a sealing step is started. The material of the cap is silicon with (100) surface
(Si) plate is used. This Si plate is etched with an aqueous solution of potassium hydroxide (KOH) to form a ring-shaped convex portion 12 at a position corresponding to the insulating airtight ring 5 of the transparent quartz substrate 1.

Then, tin (Sn) is formed on the surface of the convex portion 12 in a ring shape.
Is formed by vapor deposition and patterning. The cap solder bump 11 is overlaid on and adhered to a metal film (for example, Au) 4 having good solder wettability, and heated to 200 ° C. for hermetic sealing.

Next, first, only the cap 10 is cut outside the insulating airtight ring 5 using a dicing saw, and then the quartz substrate 1 is cut for each optical semiconductor chip 2. Then, as shown in FIG. 1 (b), an optical receiver is completed in which the optical fiber 14 is attached and the optical semiconductor chip 2 composed of a photodiode is hermetically sealed.

Since the relative position accuracy of the optical semiconductor device 2 in the transparent substrate 1 is good, if the optical fibers 14 are arranged at the same pitch as the optical semiconductor device 2, the photodiodes arranged two-dimensionally can be used. Needless to say, the optical coupling that can be performed collectively on a wafer basis with the optical fibers 14 arranged two-dimensionally.

Next, a second embodiment will be described with reference to FIG. The present invention uses a photodiode array 20,
The optical fiber array 19 whose tip is obliquely polished is bonded to the transparent substrate 1.

The bonding of the optical fiber array 19 was performed after the transparent substrate 1 was divided into the chip substrates 13. Other parts are the same as in the first embodiment. FIG. 3B shows FIG.
FIG. 2A is a cross-sectional view taken along line AA ′.

Next, in a third embodiment, as shown in FIG.
This is an example in which a transparent substrate 1 on which a lens 9 is formed on a glass plate by using an ion exchange method and a glass substrate 21 having a thickness necessary for adjusting a focal length are laminated and used. FIG.
Although omitted here, it goes without saying that the hermetic sealing is performed using the insulating hermetic ring 5 and the hermetic sealing cap 10 as in the first embodiment.

Next, a fourth embodiment is shown in FIG. In this embodiment, a component equivalent to the combination of the transparent substrate 1 and the optical fiber device 16 of the above embodiment is attached to a V-groove Si substrate 24 on the surface of which a SiO ₂ film (1a) is bonded. The groove is replaced by an optical fiber device 16a. Although omitted in FIG. 5, it goes without saying that the hermetic sealing is performed using the insulating hermetic ring 5 and the hermetic sealing cap 10 as in the first embodiment.

FIG. 6 shows an example in which a semiconductor laser is hermetically sealed using the present invention. First, Ti and Au are vacuum-deposited on the surface of a transparent substrate 1 on which a lens 9 is formed on a glass plate by an ion exchange method, a semiconductor laser chip 23 is bonded, and an electrode pattern 3 for wiring is formed. Thereafter, an insulating airtight ring 5 and a coating 4 are formed.

Next, three layers of polyimide films having different refractive indexes are spin-coated, and an optical waveguide 22 with an oblique mirror is formed by photolithography and dry etching. Next, the semiconductor laser chip 23 is bonded and hermetically sealed with the cap 10.

In the case of the semiconductor laser chip 23, electrical bonding can be performed only by bonding, so that it is not necessary to perform wire bonding as in the previous examples.

[0029]

According to the present invention, a large number of optical semiconductor chips are first mounted on a wafer-shaped transparent substrate, and then the wafer-shaped cap is used for hermetic sealing as it is. Production becomes possible. In addition, since a cap is formed by using an Si wafer and the projections on the lower surface of the cap are formed by etching, also on a wafer basis, the cost of the cap is reduced. As a result, the cost of the optical semiconductor device is significantly reduced.

Further, since the optical fiber is set in parallel with the substrate as in the second to fourth embodiments, the optical semiconductor device has an effect of reducing the thickness, and the method of FIG. When the electrode pattern is formed at a desired position, the optical coupling is performed without adjustment only by bonding the chip 2. Further, in the method of FIG. 6, since the waveguide and the electrode pattern are formed by lithography, the positional accuracy of the lens, the waveguide and the electrode pattern is improved, and there is an effect that optical coupling is performed without adjustment.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of a first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory view of a third embodiment of the present invention.

FIG. 5 is an explanatory view of a fourth embodiment of the present invention.

FIG. 6 is an explanatory diagram of a fifth embodiment of the present invention.

FIG. 7 is an explanatory view of a conventional example.

[Explanation of symbols]

1 transparent substrate 1a SiO ₂ film 2 optical semiconductor chip 3 electrode pattern 4 film 5 insulating airtight ring 6 active portion 7 active portion electrode pattern 8 solder bumps 9 Lens 10 cap 11 cap solder bumps 12 protruding portion 13 chip substrate 14 optical fiber 15 Light 16, 16a Optical fiber device 17 Lead electrode 18 Wire 19 Optical fiber array 20 Photodiode array 21 Glass substrate 22 Optical waveguide 23 Semiconductor laser chip 24 Si substrate with V-groove

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-109357 (JP, A) JP-A-60-153184 (JP, A) JP-A-59-220982 (JP, A) 116869 (JP, A) JP-A-4-322450 (JP, A) JP-A 62-94652 (JP, U) JP-A 62-94645 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 31/02-31/119 H01L 27/15-27/148 H01L 33/00 H01S 5/00-5/50 G02B 6/42-6/43

Claims (3)

(57) [Claims] A plurality of electrode patterns (3) having solder wettability and a coating (4) having solder wettability are applied to the periphery of the electrode pattern (3) on a transparent substrate (1). Forming an insulating airtight ring (5), and removing the solder bump (8) of the optical semiconductor chip (2) having a plurality of solder bumps (8) and a convex lens (9) on the back surface. Positioning and soldering the electrode pattern (2), and the cap solder bump of the cap (10) having the cap solder bump (11) on the lower surface of the insulating airtight ring (5)
(11) soldering the optical semiconductor chip (2) by hermetically sealing the optical semiconductor chip (2); and sealing the cap (12) outside the insulating airtight ring (5) with the individual optical semiconductor chip (2). Separating the transparent substrate (1) into chip substrates (13) including the individual optical semiconductor chips (2). 2. A plurality of optical semiconductor chips (2) are two-dimensionally arranged on the transparent substrate (1) and soldered to the transparent substrate (1). 5) The cap solder bump formed two-dimensionally corresponding to
2. The manufacturing method of an optical semiconductor device according to claim 1, wherein a plurality of said optical semiconductor chips are collectively hermetically sealed by aligning and soldering a cap having said first semiconductor chip. Method. 3. Light (15) emitted from an optical fiber (14).
An optical fiber device (16) having light reflecting means for bending the optical axis of the optical fiber (14) so as to be incident on the lens (9) of the optical semiconductor chip (2) is attached to the transparent substrate (1). 3. The method for manufacturing an optical semiconductor device according to claim 1, wherein the bonding is performed.