JPH10135517A - Surface type optical element and method of manufacturing the same - Google Patents

Abstract

[PROBLEMS] To provide a small-sized and high-density surface-type optical device in which the mounting area of the optical device is reduced to near the area of the optical device chip itself, and a method of manufacturing the same. SOLUTION: An optical element 2 is formed by dicing a semiconductor wafer 8 in which optical element chips 1 are formed in a matrix, and a low-loss glass wafer 7 is formed by dicing and bonded to an optical element 2. Lost glass wafer piece 7 '
The electrode section 1 of the electric signal input / output electrode 4 with respect to the optical element chip 1 exposed on the dicing end face of the optical element 2
0, and a surface-type optical element including a soldering electrode 40 formed on the dicing end face and the back surface of the optical element 2 by being connected to the electrode cross section 10 and a method of manufacturing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar optical device and a method of manufacturing the same, and more particularly, to a small-sized and high-density surface optical device and a method of manufacturing the same.

[0002]

2. Description of the Related Art A conventional example of a planar optical device will be described with reference to FIG. Light emitting diodes, surface emitting lasers, photodiodes, and OEICs are light emitting devices that are classified as surface type optical devices. In FIG. 6, reference numeral 1 denotes a bare optical element chip that is not packaged. Reference numeral 3 denotes a light emitting surface of the optical element chip 1. The optical element chip 1 is directly adhered to the printed board 60 by the adhesive 14. And
The electrode 4 for driving and emitting light from the optical element chip 1 is drawn out and connected to the printed wiring 6 via the bonding wire 13. Reference numeral 11 denotes a frame plate that surrounds the entire optical element chip 1 including the bonding wires 13. 12 is a frame plate 11
Shown is a transparent synthetic resin that fills the inside and embeds the bonding wires 13 and the entire optical element chip 1.

[0003]

In order to mount an unpackaged optical element chip 1 on a printed board 60 at a high density, the optical element chip 1 is directly bonded to the printed board 60. And bonding wire 1
In order to protect the optical element 3, a frame plate 11 surrounding the optical element chip 1 and the bonding wires 13 and a transparent synthetic resin to be filled therein are required. Therefore, the optical element chip 1
Has a drawback that when it includes the frame plate 11, it occupies a much larger mounting area than the optical element chip 1 itself.

An object of the present invention is to provide a small-sized and high-density surface-type optical device in which the mounting area of the optical device, which has solved the above-mentioned disadvantages, is reduced to near the area of the optical device chip itself, and a manufacturing method thereof.

[0005]

An optical element is formed by dicing a semiconductor wafer on which optical element chips are formed in a matrix. The optical element is formed by dicing a low-loss glass wafer. It has an attached low-loss glass wafer piece 7 ′, and has an electrode cross section 10 of the electric signal input / output electrode 4 for the optical element chip 1 exposed on the dicing end face of the optical element 2, and is connected to the electrode cross section 10. Thus, a surface-type optical device having a soldering electrode 40 formed on the dicing end surface and the back surface of the optical device 2 was formed.

[0006] The low-loss glass wafer 7 constituted a surface-type optical element constituted by a fiber optic plate. Further, in the above-mentioned surface optical device, a surface optical device in which the soldering electrode 40 of the optical device 2 was soldered to the printed circuit board 60 was formed. Here, the optical element chips 1 of the optical element 2 are formed in a matrix on the semiconductor wafer 8, and the low-loss glass wafer 7 is attached to the semiconductor wafer 8.
The semiconductor wafer 8 and the low-loss glass wafer 7 are diced across the electrical signal input / output electrode 4 to cut out the optical element 2 and connected to the electrode section 10 exposed on the dicing end face of the optical element 2 to form a solder electrode 40. Is formed on the dicing end face and the back face of the optical element 2 to form a surface type optical element.

Then, a method of manufacturing a surface-type optical element in which a fiber optic plate is adhered as the low-loss glass wafer 7 is configured. Further, in the above-described method for manufacturing a surface-type optical element, a method for manufacturing a surface-type optical element in which the soldering electrode 40 of the optical element 2 is soldered to the printed circuit board 60 is further configured.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the embodiment shown in FIG. 3A, reference numeral 7 denotes a transparent glass wafer, and reference numeral 8 denotes a semiconductor wafer on which the optical element chips 1 are formed in a matrix. FIG. 3B shows a state where the transparent glass wafer 7 is attached to the semiconductor wafer 8. Since the optical element chip 1 is for inputting and outputting light, the adhesive 14 used for bonding is used.
Is used as a transparent adhesive. The transparent glass wafer and the transparent adhesive mean that they are transparent or have low loss in the wavelength range of light to be used, but do not mean that they are transparent to visible light. In the case of the optical element chip 1 that inputs and outputs infrared light, a Si wafer can be used instead of the transparent glass wafer.

Referring to FIG. 3C, the transparent glass wafer 7 and the semiconductor wafer 8 bonded to each other are diced and separated into units of the respective optical elements 2. Reference numeral 9 denotes a dicing cutting portion in this case. Reference numeral 7 'denotes a piece of a transparent glass wafer cut out by dicing the transparent glass wafer. FIG. 3D shows one unit of the optical element 2 separated by dicing. Here, if the dicing blade is designed to cross the pattern of the electrode 4 for inputting / outputting an electric signal to / from the optical element chip 1 of the semiconductor wafer 8, the dicing end face of the optical element 2 has a cut electrode section of the cut electrode 4. 10 is exposed.

Next, referring to FIG. 3E, a soldering electrode 40 is formed on the dicing end face and the back face of the optical element 2 by connecting to the electrode section 10. This electrode formation can be easily performed by Au evaporation or sputtering using a metal mask. Note that FIG.
(E) omits the electrode 4 ', which is substantially equivalent to FIG.

FIG. 1 shows a planar optical device, and FIG.
5 shows a state in which the soldering electrode 40 formed on the dicing end surface and the printed wiring 6 are soldered with the solder 5 to attach the optical element 2 to the printed circuit board 60. After applying cream solder to the printed wiring 6 of the printed circuit board 60 and installing the optical element 2 thereon, the printed circuit board 60 is mounted by heating the entire printed circuit board 60 to melt the solder. can do.

Here, another embodiment of the present invention will be described with reference to FIGS. The other embodiment is equivalent to the previous embodiment using the fiber optic plate FOP shown in FIG. 5A shows a perspective view of the FOP and a cross section of a part of the FOP cut in a thickness direction.
(B) shows a cross section obtained by cutting a part of the FOP of (a) in the horizontal direction. The FOP is formed by slicing a result obtained by bundling and stretching a number of elementary optical fibers, and has such a cross-sectional shape. That is, reference numeral 80 denotes a core which is a core glass having a large refractive index through which light propagates.
Numeral 0 is a coating glass which is a clad surrounding the core 80 and having a smaller refractive index than the core 80. 33 is a light absorber glass interposed between the cores 80 through which light propagates. In addition,
Although the cladding 90 is shown in an extremely enlarged scale, it is actually only a very thin coating of the core 80, and
0 occupies most of the whole FOP. The core diameter of currently commercially available FOP is about 3 μm. The light incident on one end face of the FOP propagates while being totally reflected in the parallel cores as shown in FIG. Like this, FO
P is different from a mere transparent glass wafer in that it acts to suppress the diffusion of light, thereby preventing a reduction in coupling efficiency and light interference due to diffused light.

As described above, the FOP is a component obtained by slicing an optical fiber bundle and extending it into a wafer, and has a function of guiding light from the front to the back of a cross section without diffusing light. Therefore, the transparent glass wafer 7
By using the FOP instead of the above, the diffusion of light input / output from the optical element 2 is suppressed as compared with the case of the previous embodiment. When the optical element 2 is coupled to an optical fiber or another optical element, higher coupling efficiency can be obtained. This is because a low-loss glass wafer 7 as shown in FIG.
When FOP is used as the light source, the light 15 is input and output from an area approximately equal to the light emitting surface 3 at the end face, while FIG.
When the low-loss glass wafer 7 is used as shown in (a), it can be easily understood from input and output from a much larger area than the light emitting surface 3.

[0014]

As described above, according to the present invention, a transparent glass wafer is attached to an optical element chip of an optical element, thereby protecting the optical element chip. Even after the optical element is mounted, there is no need to provide a configuration for burying and protecting the optical element in a transparent synthetic resin.

Since the optical element is soldered and fixed to the printed circuit board using the soldering electrode formed from the dicing end face to the back face of the optical element, no special bonding wire is required to lead out the electrode of the optical element. In addition, the optical element can be fixed to the printed circuit board with almost the same mounting area as the optical element itself. Also, by using an FOP instead of a transparent glass wafer, the diffusion of light input and output from the optical element is suppressed. Therefore, after the optical element is mounted on a printed circuit board, the optical element is replaced with an optical fiber or other optical element. In the case of binding, higher binding efficiency can be obtained.

After all, according to the present invention, a transparent glass wafer is attached to an optical element to protect the surface of the optical element, and a soldering electrode is formed on a dicing end face of the optical element, so that a mounting area with respect to a printed circuit board is reduced. The optical element can be mounted with miniaturization.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical element according to the present invention.

FIG. 2 is a perspective view illustrating a mounted state of an optical element according to the present invention.

FIG. 3 is a diagram illustrating a manufacturing process of the optical element according to the present invention.

FIG. 4 is a cross-sectional view showing a difference in an emitted light pattern according to the embodiment.

FIG. 5 is a diagram showing the structure of an FOP.

FIG. 6 is a perspective view illustrating a mounting state of a conventional example of a surface-type optical element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical element chip 2 Optical element 3 Light emitting surface 4, 4 'electrode 5 Solder 6 Printed wiring 7 Transparent glass wafer 7' Transparent glass wafer piece 8 Semiconductor wafer 9 Dicing cutting part 10 Electrode cross section 11 Frame plate 12 Transparent resin 13 Bonding wire 14 Adhesive 15 Outgoing light 16 FOP 33 Light absorber glass 40 Soldering electrode 60 Printed circuit board 80 Core 90 Coated glass

Claims (6)

[Claims] 1. A low-loss glass wafer piece provided with an optical element formed by dicing a semiconductor wafer having optical element chips formed in a matrix, formed by dicing a low-loss glass wafer, and attached to the optical element. An electrode cross section of an electrode for electric signal input / output with respect to an optical element chip exposed on a dicing end face of the optical element; and a soldering film formed on the dicing end face and the back face of the optical element by connecting to the electrode cross section. A surface type optical element comprising an electrode. 2. The surface-type optical device according to claim 1, wherein the low-loss glass wafer is constituted by a fiber optic plate. 3. The surface optical device according to claim 1, wherein a soldering electrode of the optical device is soldered to a printed circuit board. 4. An optical element chip of an optical element is formed in a matrix on a semiconductor wafer, a low-loss glass wafer is attached to the semiconductor wafer, and the semiconductor wafer and the low-loss element are traversed across electrodes for inputting and outputting electric signals to and from the optical element chip. A surface-type optical element characterized in that an optical element is cut out by dicing a glass wafer and connected to an electrode cross section exposed at the dicing end face of the optical element, and a soldering electrode is formed over the dicing end face and the rear face of the optical element. Manufacturing method. 5. The method for manufacturing a surface-type optical device according to claim 4, wherein a fiber optic plate is attached as a low-loss glass wafer. 6. The method of manufacturing a surface type optical device according to claim 4, further comprising: soldering a soldering electrode of the optical device to a printed circuit board. A method for manufacturing an optical element.