JP2003218137A - Semiconductor chip mounting method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor device mounting technique for mounting a semiconductor chip on a board with high alignment accuracy, wherein the images of the board and the semiconductor chip are recognized by the use of a plurality of optical systems. <P>SOLUTION: This LD chip mounting device is composed of an LD stage, a bonding stage, a bonding head, an image recognition device and the like. An optical system provided for the image recognition device is composed of an infrared transmission lighting 11 which is provided to irradiate the underside of a silicon board 3 mounted with an LD chip 1 on a bonding stage with the transmitted light at right angles, a down irradiation lighting 12 which is provided to irradiate the top surface of the LD chip 1 obliquely with the reflected light at a prescribed angle from above, and an infrared camera 13 provided upright over the LD chip 1 to recognize the images of the LD chip 1 and the silicon board 3 through the infrared transmission lighting 11 and the down irradiation lighting 12. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip mounting technique, and more particularly to an LD (Laser Diode) /
In a PD (Photo Diode) assembling apparatus, the present invention relates to a technique effectively applied to a mounting apparatus of an optical semiconductor device that mounts an LD chip on a substrate with high accuracy.

[0002]

2. Description of the Related Art According to a study by the present inventor, L
The following techniques can be considered for the D / PD assembling apparatus.

For example, in an LD / PD assembly device,
In the recognition method using infrared transmissive illumination, when the LD chip is bonded to the silicon substrate, the marker of the silicon substrate and the marker of the LD chip are overlapped, and infrared transmissive illumination (wavelength: 800 to 130) from the back surface of the silicon substrate is used.
The image obtained by 0 nm) is captured by an infrared camera (observation wavelength range: 400 to 1800 nm). In the obtained image, since the markers on the silicon substrate and the LD chip can be captured at the same time, the respective positions are measured and aligned by the recognition device, so that the silicon substrate and the LD are aligned.
The chip can be bonded with high precision.

As a technique relating to the recognition method using the infrared transmission illumination as described above, for example, Japanese Patent Laid-Open No. 200
The technique described in 0-243762 is mentioned.

[0005]

DISCLOSURE OF THE INVENTION By the way, as a result of the examination of the recognition method using the infrared transmissive illumination as described above, the following has been made clear.

For example, in the above-mentioned recognition method using infrared transmissive illumination, in the bonding, alignment in the X, Y, and θ directions is performed. Among them, in order to align in the Y direction, a chip end face is used as a marker. The edge and the edge of the V groove of the silicon substrate are recognized. At this time, the edge of the chip and the edge of the silicon substrate overlap with each other, and a recognition image cannot be obtained by infrared transmissive illumination, so that bonding cannot be performed.

Therefore, the present inventor adds epi-illumination to the image recognition by the infrared transmissive illumination when the image cannot be obtained by the infrared transmissive illumination, and captures the image by switching to the epi-illumination to recognize the image. I came up with a way to do it. That is, bonding is possible by using two recognition images of infrared transmission illumination and epi-illumination to perform recognition and alignment.

Therefore, an object of the present invention is to provide an optical semiconductor device capable of recognizing images of a substrate and a semiconductor chip by using a plurality of optical systems and aligning and mounting the semiconductor chip on the substrate with high accuracy. It provides mounting technology.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the semiconductor chip mounting method according to the present invention mounts the substrate on the stage, mounts the semiconductor chip on the substrate mounted on the stage, and displays an image of the substrate mounted on the stage. The image of the semiconductor chip mounted on the substrate is recognized using a plurality of optical systems, and based on the recognition result of the image of the substrate and the image of the semiconductor chip,
The present invention is characterized in that each step has a step of correcting the relative position between the substrate and the semiconductor chip, and the semiconductor chip is aligned and mounted on the substrate using a plurality of optical systems.

Further, in the mounting method of the semiconductor chip, the plurality of optical systems include a first optical system for radiating transmitted light and a second optical system for radiating reflected light. Further, the light source of the first optical system is an infrared transmissive illumination,
The light source of the optical system is adapted to each of the epi-illuminations.

In the semiconductor chip mounting method, the substrate is a silicon substrate having an alignment mark and a V-groove-shaped laser reflecting surface formed on the upper surface thereof, and the semiconductor chip is a laser diode chip having an alignment mark formed on the lower surface thereof. In the state where the semiconductor chip is mounted on the substrate, the transmitted light is emitted from the lower surface of the substrate, the reflected light is emitted to the upper surface of the semiconductor chip, and the image of the substrate and the semiconductor chip is taken by one or more cameras. Is to recognize.

Further, a semiconductor chip mounting apparatus according to the present invention is an image recognition apparatus for recognizing an image of a substrate mounted on a stage and an image of a semiconductor chip mounted on the substrate, and an image of the substrate and the semiconductor. When recognizing the image of the chip, the first optical system that irradiates the transmitted light and the second optical system that irradiates the reflected light, and the substrate and the semiconductor based on the recognition result of the image of the substrate and the image of the semiconductor chip. It has a positioning mechanism for correcting the relative position with respect to the chip, and is characterized in that the semiconductor chip is aligned and mounted on the substrate using a plurality of optical systems.

Therefore, according to the semiconductor chip mounting method and mounting apparatus, an image which cannot be obtained by the recognition through the infrared transmission illumination is switched to the epi-illumination to be captured as an image, and the substrate and the semiconductor chip are recognized and bonded. It becomes possible to do. As a result, since it is possible to recognize two types of infrared transmission illumination and epi-illumination,
It can be applied to various semiconductor chips. In addition, since it is possible to recognize the edge of the chip end surface, which can minimize the measurement error of recognition, it is possible to perform the bonding with higher accuracy.

That is, when the substrate is irradiated with vertical infrared transmitted light from the back surface, the amount of light is reduced at the V-groove portion on the surface of the substrate, so that the V-groove portion becomes a shadow in the recognized image. Therefore, in the alignment, the edge of the chip end face may be hidden by the shadow portion, and the recognition device cannot discriminate it. In addition, it is difficult to align the optical axis of the transmitted illumination with both the V groove and the marker from the back side because there is a problem that the light amount is reduced. On the other hand, when the optical axis of the epi-illumination is irradiated according to the angle of the V groove, the edge of the V groove is clearly displayed.

On the other hand, there is an idea that a semiconductor chip marker is used as a reference. However, the position of the marker on the semiconductor chip also causes an error from the actual laser emission point in the manufacturing process of the semiconductor chip. Therefore, the error can be minimized by considering the end face of the semiconductor chip as a reference. Therefore,
According to the present invention, an image of the edge of the end face of the semiconductor chip can be obtained, so that the bonding can be performed more accurately.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In all the drawings for explaining the embodiments, members having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

(First Embodiment) FIG. 1 is a perspective view showing a semiconductor chip mounting apparatus according to a first embodiment of the present invention, and FIG. 2 shows an optical system in the semiconductor chip mounting apparatus according to the first embodiment. Explanatory drawing, FIG. 3 is a plan view and a sectional view showing a semiconductor chip, FIG. 4 is a plan view and a sectional view showing a silicon substrate, FIG. 5 is a plan view and a sectional view showing a semiconductor module, and FIG. 6 is a semiconductor chip mounting method. FIG.

First, an example of the configuration of a semiconductor chip mounting apparatus according to this embodiment will be described with reference to FIG.

The semiconductor chip mounting apparatus of this embodiment is an LD chip mounting apparatus for manufacturing a semiconductor module using, for example, an LD, and includes an LD stage 2 for carrying the LD chip 1 and an LD chip. A bonding stage 4 for bonding 1 to the silicon substrate 3, and a bonding head 5 for transporting the LD chip 1 from the LD stage 2 to the bonding stage 4.
It comprises a silicon substrate 3 on the bonding stage 4, an image recognition device 6 for recognizing an image of the LD chip 1, and the like.

The LD stage 2 is provided with an X / Y positioning mechanism for carrying the LD chip 1, and the tray mounted automatically by the carrying mechanism or manually placed is X / Y.
The LD chip 1 in this tray is positioned at the pickup position by being driven in the X and Y directions by the positioning mechanism.

The bonding stage 4 is the LD chip 1
An X / Y positioning mechanism for bonding the silicon substrate 3 to the silicon substrate 3, a heating mechanism and the like are provided, and the silicon substrate 3 placed automatically by the transport mechanism or manually placed is X / Y.
The silicon substrate 3 is positioned at the bonding position by being driven in the X and Y directions by the positioning mechanism. Further, when the LD chip 1 is bonded to the silicon substrate 3, the silicon substrate 3 is heated to a predetermined temperature by the heating mechanism.

The bonding head 5 is provided with an X / Y / Z positioning mechanism, a collet, etc. for transporting the LD chip 1 from the LD stage 2 to the bonding stage 4.
The LD chip 1 on the LD stage 2 is vacuum-sucked by the collet, and the LD chip 1 is transferred to the bonding stage 4 on which the silicon substrate 3 is mounted by the X / Y / Z positioning mechanism, and the LD chip 1 is transferred to the silicon substrate 3. Is positioned at the bonding position.

The image recognition device 6 is equipped with a camera for recognizing the image of the LD chip 1, infrared transmission illumination, epi-illumination, etc., and is used for bonding in the irradiation of transmitted light by the infrared transmission illumination and the reflection of reflected light by the epi-illumination. Stage 4
Images of the upper silicon substrate 3 and the LD chip 1 are recognized by the camera.

Next, referring to FIG. 2, an example of an optical system in the image recognition device in the LD chip mounting device of the present embodiment will be described.

The optical system in the image recognition device 6 is composed of an optical system for irradiating the transmitted light by the infrared transmissive illumination 11 and an optical system for irradiating the reflected light by the epi-illumination 12. Infrared, epi-illumination 1
Visible rays are used for the two light sources.

In the optical system of this image recognition device 6,
On the silicon substrate 3 on which the LD chip 1 on the bonding stage 4 is mounted, the infrared transmissive illumination 11 is arranged so that the transmitted light is perpendicular to the lower surface of the silicon substrate 3 and is obliquely above the upper surface of the LD chip 1. The epi-illumination 12 is arranged so that the reflected light is emitted at a predetermined angle from the LD.
With the infrared camera 13 vertically arranged above the chip 1, the L by the infrared transmission illumination 11 and the epi-illumination 12
Images of the D chip 1 and the silicon substrate 3 can be recognized.

Next, an example of the structure of the LD chip, silicon substrate, and module will be described with reference to FIGS. 3 to 5, (a) is a plan view,
(B) is a sectional view.

As shown in FIG. 3, the LD chip 1 has two alignment marks 21 formed on the lower surface of the chip at predetermined intervals. The LD chip 1 has a rectangular planar shape and is formed with a predetermined thickness.

As shown in FIG. 4, in the silicon substrate 3, two alignment marks 31 are formed on the upper surface of the substrate with a spacing narrower than the spacing between the alignment marks 21 of the LD chip 1, and a V-groove-shaped laser reflecting surface 32 is formed. Has been formed. The silicon substrate 3 has a rectangular planar shape and is formed with different thicknesses sandwiching the V groove.

As shown in FIG. 5, the module is formed by bonding the LD chip 1 on the silicon substrate 3. In this module, the laser light emitted from the LD chip 1 is reflected by the laser reflection surface 32 of the silicon substrate 3 and irradiated. In addition, this module is the LD chip 1
After being attached to the silicon substrate 3, wire bonding, resin sealing, lead molding, etc. are performed to obtain a product.

Next, referring to FIG. 6, an example of the flow of the method of mounting the semiconductor chip in this embodiment will be described.

(1) The silicon substrate 3 is set, for example, manually on the bonding stage 4, the position of the alignment mark 31 on the silicon substrate 3 is recognized, and the position of the silicon substrate 3 is corrected based on the recognition result. (Steps S1 to S3).

(2) The tray accommodating the LD chips 1 is moved onto the LD stage 2 by, for example, automatic conveyance, the outer shape and position of the LD chips 1 in the tray are recognized, and the LD is detected based on the recognition result. The position of the chip 1 is corrected (steps S4 to S6).

(3) The LD chip 1 is held by the collet of the bonding head 5, and the LD chip 1 is held on the silicon substrate 3
Is moved to the bonding stage 4 on which is set (steps S7 and S8).

(4) The position of the alignment mark 21 of the LD chip 1 is recognized, the position of the LD chip 1 is corrected based on the recognition result, and then the collet of the bonding head 5 holding the LD chip 1 is lowered. (Steps S9 to S11).

(5) The images of the silicon substrate 3 mounted on the bonding stage 4 and the LD chip 1 mounted on the silicon substrate 3 are recognized at the same time, and the collet of the bonding head 5 is identified based on the recognition result. The position of the held LD chip 1 is corrected (steps S12, S
13).

At the time of this image recognition, by utilizing the optical system in the image recognition device 6 shown in FIG. 2 above, the transmitted light is emitted from the lower surface of the silicon substrate 3 by the infrared transmission illumination 11, and the upper surface of the LD chip 1 is irradiated. The reflected light is emitted from the epi-illumination 12 to the silicon substrate 3 and the LD by the infrared camera 13.
Capture the image of chip 1.

Particularly, in the bonding accuracy, the accuracy in the Y direction (vertical direction in FIG. 5) has a great influence on the performance of the module, so that it is necessary to perform the positioning with high accuracy. At the time of recognition in the Y direction, the silicon substrate 3 uses the edge of the V groove of the laser reflection surface 32 as a reference line for recognition,
The LD chip 1 is based on the edge of the end face on the laser emission point side. In this positioning operation, if the end surface of the LD chip 1 is hidden in the shadow of the V groove of the silicon substrate 3, the infrared transmission illumination 11 cannot recognize the LD chip 1. At this time, the V groove of the silicon substrate 3 becomes a shadow,
The shaded portion X shown in FIG. 5 becomes an image in which it is painted black.

However, as in the present embodiment, the epi-illumination 12 is installed in addition to the infrared transmissive illumination 11 and the epi-illumination 12 is used, whereby the end face of the LD chip 1 can be recognized. . That is, it has been confirmed by experiments that the image obtained by the epi-illumination 12 can be sufficiently used as a recognition image even when the end surface of the LD chip 1 is hidden behind the V groove of the silicon substrate 3.

(6) The holding of the bonding head 5 by the collet is released, the LD chip 1 is bonded on the silicon substrate 3 set on the bonding stage 4, and then the collet is retracted (step S14,
S15). As described above, the LD chip 1 can be bonded onto the silicon substrate 3.

Therefore, according to the LD chip mounting apparatus of this embodiment, the image recognition apparatus is composed of the optical system for irradiating the transmitted light by the infrared transmissive illumination 11 and the optical system for irradiating the reflected light by the epi-illumination 12. By including 6, the image which cannot be obtained by the recognition by the infrared transmission illumination 11 is switched to the epi-illumination 12 to be captured as an image, and the images of the LD chip 1 and the silicon substrate 3 can be recognized and bonding can be performed.

As a result, since the infrared transmission illumination 11 and the epi-illumination 12 can be recognized in two ways, various LD chips 1 can be dealt with. Further, since the recognition error can be reduced and the edge of the end face of the LD chip 1 can be recognized, the bonding can be performed with higher accuracy.

(Second Embodiment) FIG. 7 is an explanatory diagram showing an optical system in a semiconductor chip mounting apparatus according to a second embodiment of the present invention.

Like the first embodiment, the semiconductor chip mounting apparatus of the present embodiment is an LD chip mounting apparatus for manufacturing a semiconductor module using an LD, for example. The difference is that the light source of the epi-illumination is changed from visible light to infrared light in the optical system in the image recognition apparatus.

That is, in the LD chip mounting apparatus of the present embodiment, the optical system in the image recognition apparatus irradiates the transmitted light by the infrared transmissive illumination 11 using the infrared light source as an example shown in FIG. The optical system and the optical system that irradiates reflected light by epi-illumination 12a using infrared light as a light source, and the infrared transmissive illumination 11 is arranged so that the transmitted light is radiated perpendicularly to the lower surface of the silicon substrate 3.
The epi-illumination 12a is arranged on the upper surface of the D chip 1 obliquely from above so as to irradiate the reflected light at a predetermined angle, and the infrared camera 13 vertically arranged above the LD chip 1 allows the infrared transmissive illumination 11 and the epi-illumination. The image by the illumination 12a can be recognized.

Therefore, according to the LD chip mounting apparatus of this embodiment, even when the light source of the epi-illumination 12a is changed from visible light to infrared light, the same effect as in the first embodiment can be obtained. Particularly in the present embodiment, the epi-illumination 1
By using infrared rays as the light source used for 2a, it is effective when the sensitivity wavelength range of the infrared camera 13 is biased to infrared rays (when a filter or the like is used).

(Third Embodiment) FIG. 8 is an explanatory diagram showing an optical system in a semiconductor chip mounting apparatus according to a third embodiment of the present invention.

Like the first embodiment, the semiconductor chip mounting apparatus of this embodiment is an LD chip mounting apparatus for manufacturing a semiconductor module using an LD, for example. The difference is that in the optical system of the image recognition device, another visible light camera recognizes an image by epi-illumination.

That is, in the LD chip mounting apparatus of the present embodiment, the optical system in the image recognition apparatus irradiates the transmitted light by the infrared transmissive illumination 11 using an infrared light source as an example as shown in FIG. An optical system and an optical system that irradiates reflected light by epi-illumination 12 using visible light as a light source, and infrared transmissive illumination 11 is arranged so that transmitted light is radiated vertically to the lower surface of silicon substrate 3.
An infrared camera 1 vertically arranged above the LD chip 1.
3, the infrared transmission illumination 11 enables the image to be recognized, and the epi-illumination 12 is arranged on the upper surface of the LD chip 1 so as to irradiate the reflected light at a predetermined angle from above the LD chip 1 and above the LD chip 1. The visible light camera 42 arranged horizontally via the half mirror 41 allows the epi-illumination 1
The image by 2 can be recognized.

Therefore, according to the LD chip mounting apparatus of this embodiment, even when an image from the epi-illumination 12 is recognized by another visible light camera 42 via the half mirror 41, it is the same as in the first embodiment. The effect of
In particular, in the present embodiment, when the infrared camera 13 of the infrared transmission illumination 11 and the visible light camera 42 of the epi-illumination 12 are installed, when the sensitivity wavelength range of the infrared camera 13 is biased to infrared rays (visible range). It is effective when using a cut filter, etc.).

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

For example, in the above embodiment, L
Although the case where the invention is applied to an LD chip mounting apparatus when manufacturing a semiconductor module using D has been described, it can be applied to a PD chip mounting apparatus, a flip chip bonder for various chips, a die bonder, and the like. It can be widely applied to mounting devices having a plurality of optical systems for alignment.

[0055]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1) By aligning and mounting a semiconductor chip on a substrate using a plurality of optical systems, an image that cannot be obtained by recognition by infrared transmissive illumination is captured as an image by switching to epi-illumination, It is possible to recognize the substrate and the semiconductor chip and perform highly accurate bonding.

(2) Since an image can be recognized by two types of infrared transmission illumination and epi-illumination, it is possible to cope with various semiconductor chip bonding.

(3) Since the measurement error of recognition can be minimized and the edge of the end face of the semiconductor chip can be recognized as an image, the bonding can be performed more accurately.

[Brief description of drawings]

FIG. 1 is a perspective view showing a semiconductor chip mounting apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an optical system in the semiconductor chip mounting apparatus according to the first embodiment of the present invention.

3 (a) and 3 (b) are a plan view and a cross-sectional view showing a semiconductor chip in the semiconductor chip mounting apparatus of the first embodiment of the present invention.

4A and 4B are a plan view and a cross-sectional view showing a silicon substrate in the semiconductor chip mounting apparatus according to the first embodiment of the present invention.

5A and 5B are a plan view and a cross-sectional view showing a semiconductor module in the semiconductor chip mounting apparatus according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing a semiconductor chip mounting method in the semiconductor chip mounting apparatus according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an optical system in a semiconductor chip mounting apparatus according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an optical system in a semiconductor chip mounting apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

1 LD chip 2 LD stage 3 Silicon substrate 4 Bonding stage 5 Bonding head 6 Image recognition device 11 Infrared transmission illumination 12,12a Epi-illumination 13 infrared camera 21 alignment mark 31 alignment mark 32 Laser reflective surface 41 Half mirror 42 visible light camera

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinichiro Watase             3-3 Fujibashi, Ome City, Tokyo 2 Hitachi Higashi             Inside Kyo Electronics Co., Ltd. (72) Inventor Susumu Tachibana             1410 Inada Stock Company, Hitachinaka City, Ibaraki Prefecture             Hitachi, Ltd. Digital Media Products Division             Within (72) Inventor Koji Sato             1410 Inada Stock Company, Hitachinaka City, Ibaraki Prefecture             Hitachi, Ltd. Digital Media Products Division             Within F term (reference) 5F047 FA71 FA72                 5F073 DA35 FA13 FA23 FA30

Claims (5)

[Claims] 1. A step of mounting a substrate on a stage, a step of mounting a semiconductor chip on the substrate mounted on the stage, an image of the substrate mounted on the stage, and the substrate A step of recognizing the image of the semiconductor chip mounted on a substrate using a plurality of optical systems, and based on the recognition result of the image of the substrate and the image of the semiconductor chip, relative between the substrate and the semiconductor chip. A step of correcting the position, wherein the semiconductor chip is aligned and mounted on the substrate using the plurality of optical systems. 2. The method for mounting a semiconductor chip according to claim 1, wherein the plurality of optical systems include a first optical system that radiates transmitted light.
A method of mounting a semiconductor chip, comprising: a second optical system that emits reflected light. 3. The method for mounting a semiconductor chip according to claim 2, wherein the light source of the first optical system is infrared transmissive illumination, and the light source of the second optical system is epi-illumination. Semiconductor chip mounting method. 4. The method for mounting a semiconductor chip according to claim 2, wherein the substrate is a silicon substrate having an alignment mark and a V-groove-shaped laser reflection surface formed on an upper surface thereof, and the semiconductor chip has an alignment surface formed on a lower surface thereof. A laser diode chip in which a mark is formed, in a state where the semiconductor chip is mounted on the substrate, irradiates the transmitted light from the lower surface of the substrate, and irradiates the reflected light to the upper surface of the semiconductor chip. A method for mounting a semiconductor chip, comprising recognizing images of the substrate and the semiconductor chip with one or more cameras. 5. An image of a substrate mounted on the stage,
An image recognition device that recognizes an image of a semiconductor chip mounted on the substrate, and a first optical system that emits transmitted light and a reflected light when recognizing the image of the substrate and the image of the semiconductor chip. A plurality of optical systems having a second optical system for irradiating and a positioning mechanism for correcting the relative position between the substrate and the semiconductor chip based on the recognition result of the image of the substrate and the image of the semiconductor chip. A semiconductor chip mounting apparatus, characterized in that the semiconductor chip is aligned and mounted on the substrate by using.