JPH08313746A - Optical element and its packaging method - Google Patents

Abstract

PURPOSE: To make positioning possible with high accuracy by clamp a non-connected optical element having plural electrodes with a chuck with a fine adjustment mechanism, finely adjusting the optical element laterally with an optical axis and searching an optimum position by the peak of light output force. CONSTITUTION: The un-connected optical element 1 having the two soldered electrodes 3 on the rear surface is clamped by the insulator (glass) air chuck having the fine adjustment mechanism 12 and this optical element 1 is pressed to a substrate side electrode 6 for emission of a semiconductor laser and is energized to a light emission state at the time of positioning the end face light emission type semiconductor optical element 1 onto an optical waveguide 5 disposed on a substrate 4. The fine adjustment of the optical element 1 laterally with the optical axis repeated by the fine adjustment mechanism 12, by which the optimum position of the optical element 1 with respect to the incident part of the optical waveguide 5 is searched with the peak of the light output. At this time, the chuck 11 is constituted of the insulator (glass) to allow the transmission of light and, therefore, the observation of the end face of the optical element 1 with a camera 21 disposed above the chuck 11 is possible and consequently, the measurement of the relative moving quantity of the optical element 1 is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device and its mounting method.

[0002]

2. Description of the Related Art Conventionally, as a method for mounting an optical element,
The abutting surface for positioning is set on the optical element and the board to be mounted, the accuracy is increased, and the reference surface of the optical element is pressed against the abutting surface of the reference board to improve the accuracy between the board and the optical element. A method of securing (Japanese Patent Laid-Open No. 5-196844) has been proposed.

Further, a positioning electrode is provided on the substrate so as to have a positional accuracy different from that of the light emitting electrode of the optical element with respect to the optical waveguide, and two electrodes on the substrate are used for lateral positioning. A method for ensuring the positional accuracy between the optical element and the optical waveguide by passing a current between the electrodes and between the electrodes provided on the optical element having the same size as that of the electrode and monitoring the electrical continuity therebetween (Japanese Patent Laid-Open No. 2-58).
No. 005) is proposed.

Further, the optical element is held by a chuck made of an electric conductor, the optical element is caused to emit light by energization through electrodes provided on the chuck and the substrate, and the output value thereof is observed on a monitor for positioning. (JP-A-63-213804) has also been proposed.

[0005]

In the conventional positioning method in which the optical element is not caused to emit light, the reference surface or the processed surface of the outer shape is measured or abutted to perform the positioning on the substrate. Therefore, in order to perform highly accurate positioning and minimize the optical loss due to the mounting of the optical element, both the optical element and the substrate require extremely high processing accuracy. Further, since there are variations in the positions of the active layer, which is the light emitting point of the optical element, and the waveguide on the substrate, the final mounting accuracy is a value that takes that value into consideration.

In addition, when positioning is performed while actually emitting light from the optical element, the processing accuracy of the optical element and the substrate is not required, so that the optical waveguide and the optical element can be mounted at the optimum position without lowering the bonding efficiency. It is necessary to energize an unconnected optical element under the same conditions as when it is actually mounted, emit light, and measure the optical output value.

An object of the present invention is to achieve high-precision positioning by emitting or receiving light under the same conditions as when actually mounting an unconnected optical element.

A second object of the present invention is to efficiently electrically connect unconnected optical elements.

A third object of the present invention is to provide an optical element which is optimal for positioning while emitting light in an unconnected state.

A fourth object of the present invention is to fix the positioned optical element with high accuracy.

[0011]

According to the present invention, there is provided an air chuck made of an insulator to which a fine movement mechanism is added for grasping and finely moving an optical element, a jig for fixing a substrate including a waveguide, and a jig on the substrate. A probe that applies electricity to the electrodes and a device that measures the optical output value emitted from the waveguide are provided, which is used to position and fix the optical element with two electrodes on the bottom surface on the substrate with the optical waveguide with high accuracy. It is a thing.

[0012]

With the above-mentioned structure, the unconnected optical element can be held by the chuck made of an insulator, and can be finely moved vertically and horizontally with respect to the optical waveguide on the electrode of the substrate. And
Light is emitted when it is pressed against the electrodes, and accurate positioning can be performed on the substrate by the peak value incident on the optical waveguide.

Further, since the chuck is made of an insulator (eg, glass) that can transmit light, the end surface of the optical element is installed above the chuck when positioning the optical element while making the optical element emit light. Since it can be observed by the camera, the relative movement amount of the optical element can be measured, the optical element can be accurately moved, and highly accurate positioning can be performed.

Further, since the electrodes formed on the optical element are formed on the lower surface so as to be separated from each other on both ends, there is no light emission due to the electrode piece contact, and the optical element can emit light in the same correct posture as when actually mounted. It is possible to detect the optical output value and perform accurate positioning.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a positioning device for an optical element according to the present invention. 1 is an edge emitting semiconductor optical device, 2 is an active layer of the semiconductor optical device, 3 is a solder electrode of the semiconductor optical device,
Reference numeral 4 is a substrate, 5 is an optical waveguide provided on the substrate, 6 is a substrate-side electrode for emitting a semiconductor laser provided on the substrate, 11
Is an insulator (glass) air chuck, 12 is a fine movement mechanism for finely moving the air chuck, and 21 is a camera for observing the semiconductor optical device.

FIG. 2 is a side view of the chuck including a light emitting and measuring system. 14 is a sensor for measuring the positions of the substrate and the chuck, 22 is a monitor for observing the image of the camera 21, 31 is an electrode of the substrate. A light emitting probe for supplying a current to the device, 33 is a large-diameter optical fiber for inputting the light output from the optical waveguide, 51 is a control computer, 52 is an image processing device for processing the image of the camera, and 53 is a light for the probe. A power supply device for supplying an arbitrary current for driving the element, 54 is an optical power amplifier for measuring the output value of light.

FIG. 3 is a perspective view of the entire system including a positioning and transfer mechanism. 13 is a robot for transporting optical elements, 32 is a substrate fixing base plate coarse movement mechanism, 34 is a substrate positioning jig, and 35 is a substrate positioning jig. Is a substrate positioning plate, 36 is a substrate pressing pin, 41 is an optical element pallet, 42 is an optical element pallet positioning base plate, 43 is a pallet fine movement mechanism, 44 is a waveguide substrate positioning base plate, and 45 is a substrate transfer robot. Four
Reference numeral 6 represents a substrate chuck.

Next, the configuration and function of each part will be described with reference to the above figures.

The substrates 4 are regularly arranged on the waveguide substrate positioning base plate 44. Then, the substrate transfer robot 4
5 moves to the upper side of the substrate, and is gripped by the substrate chuck 46. The grasped substrate 4 is moved and set on the substrate positioning jig 34 by the substrate transfer robot 45. The substrate 4 placed on the substrate positioning jig 34
Is pressed against the board positioning plate 35 by the board pressing pin 36, and the positional accuracy in the horizontal direction with respect to the board positioning jig 34 is obtained by the pressing. Further, in the vertical direction, a suction hole for vacuum suction of the substrate 4 is provided at the center of the substrate positioning jig 34 to maintain the vertical accuracy.

The optical element 1 is housed in the optical element pallet 41 and fixed on the optical element pallet positioning base plate 42. The optical element 1 is moved onto the optical element pallet 41 at the same time as the insulator air chuck 11 by the optical element conveying robot 13, and the optical element observing camera 21 moves the optical element pallet 41.
The upper position is observed, and the pallet fine movement mechanism 43 moves the optical element pallet positioning base plate 42 and the optical element pallet 41 to a position where the insulator air chuck 11 can hold. Then, it is gripped by the insulator air chuck 11 by vacuum suction. The grasped optical element 1 is moved above the substrate 4 fixed on the substrate positioning jig 34 by the optical element transport robot 13.

The moved optical element 1 is an insulator air chuck 1.
The fine movement mechanism 12 for moving 1 brings it closer to the substrate 4,
At that time, since it is necessary to define the distance between the optical element 1 and the substrate 4, the distance sensor 1 provided on the insulator air chuck 11
4, the upper surface of the optical element 1 and the upper surface of the waveguide 5 are both within the depth of focus of the observation camera 21, and the optical element electrode 3 and the substrate side electrode 4
Position where they do not contact (eg electrode clearance 10um ± 3u
Stop at m).

The optical element 1 is measured in horizontal position with respect to the optical waveguide 5 by the observation camera 21 and the image processing device 52,
The laser light emitted from the active layer 2 of the optical element 1 is fixed with an accuracy (for example, within ± 10 μm) of being incident on the optical waveguide 5,
The substrate 4 is moved by using the substrate base plate coarse movement mechanism 32. Also,
After the substrate 4 is moved, the light emitting probe 31 is connected to the substrate side electrode 6 for emitting light from the optical element.

Next, the waveguide 5 of the optical element 1 is finely adjusted. Here, the mounting accuracy in the lateral direction with respect to the optical axis of the optical element 1 on the waveguide 5 is required to be very high.
(For example, within ± 0.5 μm) Then, the light is actually emitted while moving the optical element 1 to find the position where the light peaks with respect to the optical waveguide 5. However, since the optical element 1 is not connected, the optical element 1 is lowered by the fine movement mechanism 12 to connect the optical element electrode 3 to the substrate side electrode 6. Electrode 6 on substrate 4
It is confirmed by energizing that the two optical element electrodes 3 of the optical element 1 are connected to each other, and a current for driving the optical element is passed from the power supply device 53 through the light emitting probe 31, the substrate side electrode 4, and the optical element electrode 3 to Light (laser) is emitted from the active layer 2 by flowing it into the element 1. The emitted light (laser light) enters the optical waveguide 5, passes through the large-diameter optical fiber 33, and is transmitted to the optical power amplifier 54.
Is measured at. Next, the optical element 1 is moved up to the initial position by the fine movement mechanism 12 and moved in the horizontal direction with respect to the waveguide 5 by a minute amount (for example, 0.1 μm). Then, this algorithm is repeated for the positioning error due to the outer shape of the optical element 1. (In the case of the first embodiment, the positioning accuracy is ± 10 μm,
When the operation is summarized, the optical element 1 descends → energization confirmation → light emission → optical output value measurement → optical element 1 increase → optical element 1 minute feed. The algorithm is the control computer 51. Controls the optical power amplifier 54, the light emitting power source 53, and the minute feeding mechanism 12 by
The measurement operation is performed. The optical peak value of the data is calculated by the control computer 51, the most efficient position of the optical element 1 with respect to the optical waveguide 5 is calculated, and the optical element 1 is moved to the position on the substrate 4 by the fine movement mechanism 12. It is fixed to the substrate 4 via solder which is an electrode.

At this time, if the optical element 1 held by the insulator chuck 11 is displaced, the measurement cannot be performed correctly. Therefore, the observation camera 21 installed above the optical element 1 includes the end surface of the optical element 1. The image 22 is measured. Then, the moving distance of the optical element 1 is calculated by the image processing device 52 based on the image 22 and is fed back to the data when the peak is obtained, so that the correct peak position can be measured.

Further, FIG. 4 shows a side view of the bonded state of the optical element 1 and the substrate 4. When pressing the optical element 1 against the electrode 6,
For example, when the entire lower surface of the optical element 1 is an electrode (FIG. 4 (a)), there is no problem with the light emission condition if the entire surface is pressed, but if it is slightly inclined (FIG. 4 (b)).
Even if it hits one side, light will be emitted by the other electrode protruding upwards, and the height direction will shift from the actual position, and data with a large error will be measured. In order to eliminate the error factor, two electrodes are formed on the lower end surface of the optical element 1. (FIG. 5 (c)) When these two electrodes are tilted, one of them is separated from the other, so that current cannot be supplied and light is not emitted. (Fig. 4
(D)) Therefore, a correct peak can be calculated without measuring an incorrect value.

Further, at the time of this positioning, the optical element 1 was energized by pressing the electrode 3, but when the conductive material was filled between the optical element and the substrate as shown in FIG.
This substance is a conductive paste 61 or a conductive adhesive 62.
But it is possible. In this case, it is not necessary to vertically move the electrode 3 against the electrode 6, and the conductive paste 61 and the conductive adhesive 62, which are fluids, are used to conduct electricity, so that the optimum position for mounting is searched only by lateral movement. I can do things. After positioning, the optical element 1 can be fixed at an arbitrary position by solidifying it by applying energy such as heat from the outside.

[0028]

According to the present invention, in an optical element adjusting and mounting method and apparatus, the effect of improving the mounting accuracy of an optical element having no reference plane on an optical waveguide and the adjustment of the post-process due to the improvement of the accuracy are unnecessary. And

[Brief description of drawings]

FIG. 1 is a perspective view showing an optical element positioning device of the present invention.

FIG. 2 is a side view including the optical element positioning device of the present invention and its system.

FIG. 3 is a perspective view of the entire apparatus including the optical element transfer mechanism of the present invention.

FIG. 4 is a side view showing the states of the optical element of the present invention and the electrodes of the substrate.

FIG. 5 is a side view showing a case where the space between the optical element of the present invention and the substrate is filled with a conductive material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical element, 2 ... Optical element active layer, 3 ... Optical element electrode, 4 ... Substrate, 5 ... Optical waveguide, 6 ... Substrate energizing electrode, 11 ... Insulator (glass) air chuck, 12 ... Fine movement mechanism, 21 … Observation camera.

Claims (6)

[Claims] 1. When positioning a light emitting element on a waveguide,
An unconnected optical element having two electrodes on the bottom surface is gripped by a chuck made of an insulator having a fine movement mechanism, and the optical element is pressed against the electrode of the waveguide to energize it, and the optical axis By repeating the fine movement of the optical element to the left and right,
A method of positioning an optical element, characterized in that an optimum position of the optical element with respect to an incident portion of the waveguide is searched by a peak of optical output. 2. A light emitting element is pressed against a waveguide to emit light, and when the output value is measured and the positioning is performed, the element is confirmed by confirming the electric conduction state between two electrodes attached to both ends of the lower surface of the light emitting element. A positioning method characterized in that the variation in the height direction due to one-sided contact is reduced, and stable light output and high positioning accuracy are obtained. 3. The light emitting device according to claim 1, wherein the light emitting device is a light receiving device, and the light emitted from the optical waveguide side is received by the light receiving device which is finely moving, and the current value is monitored through an electrode to form an optical device. An optical element positioning method for positioning at an optimum position with respect to an optical waveguide. 4. An optical element having two light-emitting electrodes formed on both ends of a lower surface for accurately reproducing the position in the height direction when the maximum value of the output value is monitored by causing the optical element to emit light on the waveguide. An optical element characterized by the above. 5. When the optical element is positioned on the waveguide, terminals are connected with a conductive paste to conduct electricity, and the optical element in the light emitting or receiving state is moved forward, backward, leftward, and rightward with respect to the optical axis. A method for mounting an optical element, characterized in that the optical element is located at an optimum position by searching for a position where 6. A method of positioning an optical element according to claim 5, wherein the conductive paste is a conductive adhesive.