JPH0645652A - Die-bonding device and method of optical head - Google Patents

Abstract

PURPOSE:To achieve a die-bonding device of an optical head which can bond a light emitting element with a high position accuracy by allowing a probe to contact a chip for actually emitting light and detecting the position deviation and then compensating it. CONSTITUTION:When probes 76 and 77 are brought into contact with an electrode 78 and a light emitting element 44 and light is emitted from the tip surface toward a prism 42, the light source within a lamp case is lit, a characteristic part 81, a light distribution Q, and a characteristic part 82 are observed by a camera 21, a camera 22, and a camera 23, respectively, and then the positions are detected by the cameras 21 and 23. Then, a center line L1 of the light distribution Q is obtained, the cross angle with a proper center line L0 is obtained, and then the position deviation DELTAtheta in theta direction is detected, a motor 63 is driven for rotating a circular plate 62 horizontally and rotating a collet 72 by DELTAtheta. Therefore, a chip 43 is rotated horizontally on a substrate 41 for compensating the position deviation DELTAtheta in theta direction, bonding can be made with a high position accuracy, and an optical head can be assembled with an improved workability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die bonding apparatus and a die bonding method for an optical head, and more particularly, to detecting and correcting a positional deviation of a chip which emits light in the XYθ directions, so that the chip is mounted on a substrate. The present invention relates to a die bonding apparatus and a die bonding method for an optical head to be bonded.

[0002]

2. Description of the Related Art An optical head used as a reading means for a compact disc or the like emits light emitted from a light emitting element to an information carrier such as a compact disc, and the reflected light is received by a light receiving element so that information is recorded. For reading, a mirror for refracting light in a predetermined direction is arranged in the optical path from the light emitting element to the light receiving element. However, in such a conventional optical head, there is a limit to miniaturization and compaction because a mirror needs to be incorporated therein.

Therefore, in recent years, a small and compact optical head has been proposed. In this optical head, a chip including a light emitting element composed of a laser diode and a prism are integrally assembled on a substrate, and light emitted from the light emitting element and reflected by an information carrier is disposed inside the prism. Since it is incident on the light receiving element, there is an advantage that a mirror and a mounting means for the mirror are unnecessary and the device can be made compact and compact.

[0004]

Since the light emitting element and the light receiving element of the optical head are integrally assembled on the same substrate, the light emitting element must be mounted on the substrate with high positional accuracy with respect to the light receiving element. However, at present, a technique for efficiently mounting a light emitting element on a substrate with high positional accuracy and assembling an optical head has not yet been proposed.

Therefore, an object of the present invention is to provide a die bonding apparatus and a die bonding method for an optical head, which are capable of bonding a light emitting element to a substrate with high positional accuracy and workability.

[0006]

According to the present invention, a chip including a light emitting element mounted on a substrate is pressed by a collet, a probe is brought into contact with the chip in this state to energize the chip, and light is emitted from the chip. Then, this light is observed by an observation means such as a camera to detect the displacement of the chip in the XYθ directions. Then, while the chip is being pressed by the collet, the collet is moved in the XYθ directions relative to the substrate to correct the displacement in the XYθ directions.

[0007]

According to the above construction, after the chip is mounted on the substrate, the probe is brought into contact with the chip to actually emit light to detect the positional deviation of the chip, and the chip is relatively moved in the XYθ directions with respect to the substrate. Since it is configured to correct the positional deviation detected by moving it to, it is possible to realize extremely high positional accuracy, and moreover, it is possible to detect the positional deviation of the chip and correct the detected positional deviation in quick succession. ,
The optical head can be assembled with extremely good workability.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view of a die bonding apparatus. Reference numeral 1 is a table, and a chip supply unit 2 is provided on the left side of the upper surface thereof. The chip supply unit 2 includes a turntable 3 and an XY table 4 that moves the turntable 3 in the XY directions.
Holds five wafers 5.

Behind the table 1 is a guide block 11
Is provided. A guide rail 12 in the Y direction is provided on the front surface of the guide block 11, and the first head 13 and the second head 13 which slide along the guide rail 12 are provided.
Head 14 and third head 15 are provided. The three heads 13, 14 and 15 are driven by a driving unit (not shown) and simultaneously reciprocate in the Y direction, so that the first head 13 transfers the chips of the wafer 5 to the correction stage 16 and the second head. Head 14 is a correction stage 16
The chip whose misalignment has been roughly corrected by is transferred onto a substrate (described later), and the third head 15 applies the bond of the bond tray 17 to the substrate. Reference numeral 18 is a keyboard, and 19 is a monitor television.

A column 20 is erected at a corner of the table 1. The column 20 holds a first camera 21, a second camera 22, and a third camera 23. A stage 24 is provided below the column 20. This stage 24 has a wafer 2 equipped with a substrate.
5 are provided. The stage 24 is installed on the slider 26. The slider 26 slides along the Y-direction rail 27 by the drive of the motor 28. Further, the slider 26 slides along the X-direction rail 30 by the drive of the motor 29. Therefore, the stage 24
It is moved in the XY directions by driving the motors 28 and 29.

A lamp case 31 is provided behind the column 20. The light of the lamp case 31 passes through the optical fiber housed in the cable 32 and illuminates the illumination light of the cameras 21, 22, and 23 toward the wafer 25.

FIG. 2 is a perspective view of a main portion, and FIG. 3 is a partially enlarged perspective view thereof. Wafer sheet 25a of the wafer 25
(See FIG. 5) A large number of silicon substrates 41 are attached to the top. The prism 42 is previously bonded to the upper surface of the substrate 41. As shown in FIG.
The prism 42 and the chip 43 are integrally bonded to each other to assemble the small and compact optical head described in the section of the prior art.

In FIG. 3, a light emitting element 44 such as a laser diode is bonded to the front portion of the upper surface of the chip 43, and a light receiving element 45 is provided inside the prism 42.
Is provided. The wafer 5 has a chip 43 to which a light emitting element 44 is bonded. The wafer 25 is a substrate 41 to which a prism 42 is previously bonded.
Is equipped with. Further, in FIG. 1, in a state where the stage 24 slides along the X-direction rail 30 and moves directly below the main body block 11, as described above, each of the heads 13 and 1 is moved.
As the heads 4 and 15 reciprocate in the Y direction, the third head 15 applies the bond 46 of the bond tray 17 to the upper surface of the substrate 41, and the first head 13 corrects the chip 43 on the wafer 5 to the correction stage. Then, the second head 14 mounts on the bond 46 the chip 43 whose position deviation has been roughly corrected in advance on the correction stage 16. The positional accuracy of the light emitting element 44 with respect to the prism 42 and the light receiving element 45 requires extremely high accuracy.
After the positional deviation of the chip 43 is roughly corrected by the correction stage 16, precise positional deviation is detected and corrected by means described later.

In FIG. 2, each of the cameras 21, 22, 22 is
The lens barrel 23 is held by a lens barrel 49 held by the tip of the column 20. Reference numeral 51 is a frame, and a Z-direction guide 52 is attached to the front surface thereof. Reference numeral 53 is a lifting bracket, and a slider 54 on the back surface thereof is fitted to the guide 52. Reference numeral 55 is a coil spring that connects the frame 51 and the bracket 53.

A cam 56 and a motor 57 for rotating the cam 56 are provided above the frame 51. A roller 58 that comes into contact with the cam 56 is mounted on the upper portion of the bracket 53. The motor 57 drives to drive the cam 56.
When rotates, the bracket 53 moves up and down.

A horizontal base plate 61 is held below the bracket 53. A disc 6 is provided at the front of the base plate 61.
Two are provided. The circumference of the disc 62 is fitted to the three rollers 63 (see also FIG. 4), and the disc 62 is horizontally rotatable along the rollers 63. The motor 47 and the motor 47 are provided at the rear of the base plate 61.
A cam 64 that is driven to rotate is provided.

In FIGS. 2 and 4, reference numeral 65 is a rocking lever, which is pivotally mounted so as to be horizontally rotatable around the center of the disc 62. A cam 64 is provided at the rear end of the swing lever 65.
A roller 66 that comes into contact with is axially attached. Reference numeral 67 is a coil spring that repels the swing lever 65 to bring the roller 66 into contact with the cam 64. The tip of the rocking lever 65 is connected to the disk 62, and when the motor 47 drives and the cam 64 rotates, the rocking lever 65 moves to the disk 62.
The disk 62 also horizontally rotates around the center of the disk. Above the frame 51, a Y direction adjusting screw 69 and an X direction adjusting screw 70 are provided. These screws 69,
By turning 70, the base plate 61 is slightly moved in the X direction and the Y direction to adjust its position.

In FIG. 2, a ring 71 is mounted at the center of the disc 62, and a collet 72 is held at the center of the ring 71 (see also FIG. 4). In FIG. 3, the collet 72 is a rectangular plate-shaped body, and the arms 71 extending from the four corners thereof form a ring 71 (see FIG. 2).
Held in. A slit 74 is formed in the center of the collet 72, and a circular hole 75 is formed in the side of the slit 74. A first probe 76 is inserted into the disc hole 75, and a second probe 77 is inserted into the slit 74.

When the motor 57 is driven to rotate the cam 56 and the base plate 61 descends, the collet 72 descends integrally with the base plate 61, and the projection 72a formed in a wedge shape on the lower surface thereof. , Hold down the edge of the tip 43 (see FIG. 5). Further, at that time, the probes 76, 76 are also lowered integrally with the base plate 61, the first probe 76 contacts the light emitting element 44, and the second probe 77 contacts the electrode 78 of the chip 43. Probe 76,
When electricity is applied to 77, the light emitting element 44 emits light from the tip surface thereof toward the prism 42. In FIG.
A control unit 80 controls the probes 76 and 77. In FIG. 3, the slit 74 is the camera 21, 22, 2.
The first camera 21 observes the first characteristic portion 81 on the chip 41 through the slit 74, and the second camera 22 observes the light emitted from the light emitting element 44 through the slit 74. Then, the third camera 23 observes the second characteristic portion 82. Slit 74a orthogonal to this slit 74
Is a viewing window for observing the light emitted from the light emitting element 44.

This die bonding apparatus has the above-mentioned structure, and its operation will be described below. In FIG.
The third head 15 is bonded to the substrate 41 on the wafer 25 by reciprocating the three heads 13, 14 and 15 in the Y direction while the wafer 25 on the stage 24 is moving directly below the guide block 11. 46 is applied, and the second head 14 picks up the chip 43 whose positional deviation is roughly corrected by the correction stage 16 and mounts it on the bond 46 applied to the substrate 41. By repeating this operation, the chips 43 are mounted on all the substrates 41 on the wafer 25. Next, the motor 29 rotates in the reverse direction, and the wafer 25 moves directly below the support column 20. Therefore, in FIG. 2, the base plate 61 is lowered by driving the motor 57, the collet 72 presses the chip 43 with its projection 72a as shown in FIG. 5, and the probes 76 and 77 use the electrodes 78 and the light emitting element. The light emitting element 44 is in contact with the light emitting element 44, and emits light from the tip surface thereof toward the prism 42.

FIG. 6 is a plan view of the substrate 41 in which the detection of the displacement of the chip 43 is being corrected. In the figure, the solid line shows the chip 43 before correction of the positional deviation, and the chain line shows the chip 43 after correction. As shown, the chip 43 before correction is X
There is a positional shift in the Yθ direction, and this positional shift is detected and corrected as follows. The light source in the lamp case 31 is turned on, and the first camera 21 uses the first characteristic portion 81, the second camera 22 uses the light distribution Q, and the third camera 23 uses the second characteristic part 81.
Observe the characteristic portion 82 of. By detecting the positions of the first characteristic portion 81 and the second characteristic portion 82 with the cameras 21 and 23, the positions of the substrate 41 and the prism 42 and the light receiving element 45 mounted on the substrate 41 are determined. The prism 42 and the light receiving element 45 are correctly mounted on the substrate 41 without positional displacement.

Now, as shown in FIG. 7, the center line L1 of the light distribution Q is obtained, and the intersection angle with the correct center line L0 registered in advance in the memory (not shown) of the computer (not shown) is obtained. Thus, the positional deviation Δθ in the θ direction is detected. Therefore, the collet 72 is rotated by Δθ by horizontally rotating the disc 62 by driving the motor 63 shown in FIG. At this time, since the collet 72 holds the chip 43 and the bond 46 for bonding the chip 43 to the substrate 41 is uncured, the chip 43 horizontally rotates on the substrate 41 and the direction of θ (rotation direction). The positional deviation Δθ is corrected.

In FIG. 7, the coordinates (X1, Y1) of the intersection B between the center line L1 and the front surface of the light emitting element 44 are detected and the correct intersection A registered in the memory of the computer is detected.
By calculating the difference between (X0, Y0), the positional deviation ΔX in the X direction and the positional deviation ΔY in the Y direction can be calculated. Such calculation is performed by a computer. The positional deviations ΔX and ΔY in the XY directions are maintained with the collet 72 holding the chip 43, and the motors 28 and 29 are moved.
(See FIG. 1) is driven to move the stage 24 by ΔX and ΔY in the XY directions for correction.

When the correction of the positional deviation of the tip 43 is completed as described above, the motor 57 shown in FIG. 3 is driven in the reverse direction to raise the collet 72, and the pressing state of the tip 43 is released. The probes 76 and 77 are also the light emitting element 44.
Further, the swing lever 65 is returned to the original position by separating from the electrode 78 and the motor 63. Then, by repeating the series of operations described above, the substrate 41 on the wafer 25 is
When the chips 43 are bonded to each other one after another and the positional deviation correction of the chips 43 for all the substrates 41 on the wafer 25 is completed, the wafer 25 is removed from the stage 24, and a new wafer 25 is set on the stage 24. Then, the above work is repeated.

The present invention can be applied to an optical head having a structure in which a chip having a light emitting element is bonded to a substrate having a light receiving element, and the structure of the optical head is not limited to that of the embodiment. Further, the operation sequence until the positional deviation of the chip is corrected is not limited to the above-mentioned embodiment, and the front and rear may be replaced appropriately. Further, various configurations of the apparatus are conceivable. For example, while the substrate is pressed by the collet, the collet is moved in the XY direction or the θ direction with respect to the substrate to correct the positional deviation in the XYθ directions. Is also good.

[0027]

As described above, according to the present invention, the probe is actually brought into contact with the chip, the chip is energized to cause the chip to emit light, and the light is observed to detect the positional deviation in the XYθ directions, and the state thereof is detected. Since the chip is moved in the XYθ directions relative to the substrate to correct the positional deviation, the chip can be bonded to the light receiving element with extremely high positional accuracy, and the positional deviation of the chip can be detected. Since the detected positional deviation can be corrected immediately after each other, the optical head can be assembled with extremely good workability.

[Brief description of drawings]

FIG. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of an essential part of a die bonding apparatus according to an embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of a die bonding apparatus according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of an essential part of a die bonding apparatus according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of an essential part of a die bonding apparatus according to an embodiment of the present invention.

FIG. 6 is a plan view of an essential part of a die bonding apparatus according to an embodiment of the present invention.

FIG. 7 is an enlarged plan view of an essential part of a die bonding apparatus according to an embodiment of the present invention.

[Explanation of reference numerals] 22 camera (observing means) 25 moving means in Y direction 29 moving means in X direction 41 substrate 43 chip 44 light emitting element 63 moving means in θ direction 72 collet 76, 77 probe

Claims (2)

[Claims] 1. A collet for pressing and fixing a chip including a light emitting element mounted on a substrate from above, and light from the chip is brought into contact with an electrode of the chip while the chip is pressed by the collet. A probe for emitting light, an observing means for observing the light to detect a positional deviation of the chip in the XYθ directions, and a collet in a XYθ direction relative to the substrate while the chip is pressed by the collet. A die bonding apparatus for an optical head, comprising: a moving unit that corrects the positional deviation by moving the optical head. 2. A process of bonding a chip including a light emitting element to a substrate on which a light receiving element is mounted by bonding, a process of pressing the chip against the substrate with a collet, and a probe being brought into contact with an electrode of the chip. A process of emitting light from the chip, a process of observing the light emitted from the chip by an observing means to detect a positional shift of the chip in the XYθ directions, and a process of correcting the positional shift of the XYθ directions detected in the process. In order to do so, a process of moving the collet in the XYθ directions relative to the substrate while the chip is being pressed by the collet is included, and a die bonding method of an optical head.