JPS62165948A - Semiconductor element assembling apparatus - Google Patents

Abstract

PURPOSE:To assemble an element in high accuracy by providing a sub-light source having a light for emitting a semiconductor chip by moving on an optical axis for connecting the chip with a TV camera, and a filter for transmitting the reflected light from the chip only on a predetermined region on the periphery of the axis on the axis. CONSTITUTION:The luminous flux of a W bulb 11 is reflected on the front surface of a laser chip 3a, and introduced through an interference filter 4 and an objective lens 5 to a TV camera 12. The only luminous flux of an He-Ne laser 8 which transmits the window 4a of the filter is introduced through the lens 5 to the camera 12 to reduce the number of openings. An image is processed to decide X-Y coordinates of the chip 3, Z coordinate is determined by the contrast of the image, a chuck 2 is moved to accurately position the chip 3 on an optical axis A, to be inclined around the axis to form the cleaved surface of the chip perpendicularly to the axis A. The post 14 of a stem 13 is brazed as it is. Since the position of the chip is detected by a large number of openings and the attitude of the chip is detected by small number of openings with this construction, its sensitivity is made at high level to bond at accurate position and attitude.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a semiconductor device assembly apparatus for assembling semiconductor devices such as semiconductor laser devices.

(b) Conventional technology In the past, when assembling semiconductor laser devices, etc., the post on the stem that constitutes the package of the semiconductor laser device was
As a semiconductor device assembly device for bonding laser diode chips (hereinafter referred to as LD chips), the second
The one shown in the figure is known.

First, 23 is an LD chip that is attracted to the lower end of the vacuum chuck 22. The LD chip 23 has a laser chip 23a fixed to the front part of the top surface of a submount 23b made of silicon or the like.
It is transported to the optical axes A and h of No. 5. The objective lens 25 focuses an image of the laser chip 23a on the TV camera 32. Also, on the optical axis A connecting the objective lens 25 and the TV camera 32, there is a no.
A half mirror 29 is provided, and a tungsten light bulb 31 is provided above the half mirror 29. The light from this tungsten bulb 31 is reflected on the surface of the half mirror 29, travels in the negative direction of two axes, and enters the objective lens 25.
The light is focused on the front end surface of the laser chip 23a on the LD chip 23, and the front end surface of the laser chip 23a is illuminated. At this time, the light from the tungsten bulb 31 is transmitted to the laser chip 23a.
A convex lens 30 for adjusting the spread of the light beam is provided on the optical axis B connecting the half mirror 29 and the tungsten light bulb 31 so that the light is focused on the front end surface.

The image signal of the TV camera 32 is processed by an image processing circuit, and the attitude and positioning mechanism that operates in response to the processing result determines the attitude of the LD chip 23 (tilt around the X axis, the X axis, and the z axis). and the position (X-axis, X-axis, and Z-axis directions) are adjusted. L with adjusted posture and position
The D chip 23 maintains its posture and positional relationship,
It is conveyed onto the post 34 of the stem 33 and pounded onto the post 34 with a screw material such as indium.

(c) Problems to be solved by the invention In the above conventional semiconductor device assembly apparatus, the LD chip 2
In order to improve the attitude detection sensitivity for detecting the attitude No. 3, it was necessary to reduce the numerical aperture NA of the objective lens 25. This will be explained with reference to FIG. 3 tar and FIG. 3 (bl).

Now, consider a state in which the LD chip 23 is tilted by a small angle Δα counterclockwise around the X-axis in FIG. When the numerical aperture NA of the objective lens 25 is large, the luminous flux of the reflected light from the laser chip 23a@end surface on the LD chip 23 [third
The solid thin line in the figure is captured by the objective lens 25, and almost all of it is incident on the TV camera 32. For this reason,
Even when the LD chip 23 is tilted, the brightness of the image of the front end surface of the laser chip 23a captured by the TV camera 32 is not significantly different from when the LD chip 23 is not tilted, and the LD chip It is difficult to identify whether the LD chip 23 is tilted or not, and there is a problem in that the LD chip 23 is bonded to the boss 34 in a tilted position.

If the numerical aperture NA of the objective lens 25 is made small, as shown in FIG.
The amount of reflected light from the laser chip 23a captured by the camera 32 is greatly reduced, and the difference in brightness between when the LD chip 23 is tilted and when it is not tilted is significant.
The tilt of the thousand knob 23 is easily identified. In addition, Figure 3 (
The broken lines in a) and FIG. 3 tbl indicate the tungsten bulb 3
The luminous flux from 1 is shown.

However, if the numerical aperture NA of the objective lens 25 is made small, T
The amount of light incident on the V camera 32 decreases, the jjt image quality decreases, and the position detection sensitivity for detecting positional deviations in the X-axis, X-axis, and Z-axis directions decreases.
There was an inconvenience that the chip 23 was shifted in a certain direction and was pounded.

The present invention has been made in view of the above-mentioned disadvantages, and relates to a semiconductor device assembly apparatus that enables guiponding with both posture and position errors suppressed to a low water rate.

(d) Means for Solving the Problems As a means for solving the above-mentioned disadvantages, the semiconductor element assembly apparatus of the present invention provides a semiconductor element assembly apparatus in which the emitted light connects a semiconductor chip such as an LD chip and an imaging means such as a TV camera. A sub-light source that travels on the axis and irradiates the semiconductor chip, and a filter that is provided on the optical axis and transmits the light of the sub-light source that is reflected from the semiconductor chip only in a predetermined area around the optical axis. It is something.

(E) Function In the semiconductor device assembly apparatus of the present invention, the light flux of the main light source reflected by the semiconductor chip is excluded from the wavelength component that is the same as the wavelength of the light of the sub-light source, and is captured by the effective diameter of the objective optical system. Everything that is captured can be captured by the imaging means. However, of the light flux of the sub-light source reflected by the semiconductor chip, only that within a predetermined area smaller than the effective diameter of the objective optical system around the optical axis passes through the filter and enters the imaging means. Therefore, the same result can be obtained as if the numerical aperture NA of the objective optical system had become smaller.

Therefore, if the position of the semi-quadruple chip is detected using the light from the main light source, and the attitude of the semiconductor chip is detected using the light from the sub-light source, even if the objective optical system is the same, the numerical aperture for position detection will be It is possible to have a large NA and a small numerical aperture NA for attitude detection, which increases both position detection sensitivity and attitude detection sensitivity, and improves the attitude and position of the semiconductor chip die-bonded to the bonding location. It becomes possible to reduce errors.

(f) Embodiment An embodiment of the present invention will be described below with reference to FIG.

2 is a vacuum chuck that attracts the LD chip 3 at its lower end. As described above, the LD chip 3 is composed of a submount 3b and a laser chip 3a.

4 is placed on the optical axis A and has an objective lens 5, which will be described later, in the center.
This is an annular interference filter having a window hole 4a with a diameter smaller than the effective diameter of the filter. This interference filter 4 has a helium-neon laser (hereinafter referred to as He-Ne laser), which will be described later, except for the window hole 4a.
The He-Ne laser beam (wavelength 0
．． 633 pm).

An objective lens 5 made of a convex lens is provided on the biaxial positive direction side of the interference filter 4 so that its central axis coincides with the optical axis A. This objective lens 5 forms an image of the laser chip 3a on a TV camera 12, which is also provided on the optical axis A.

On the optical axis A between the objective lens 5 and the TV camera 12,
Two half mirrors 6 and 9 are provided. The half mirror 6 is provided at an angle of 45° counterclockwise around the X-axis, and below it (in the negative direction of the y-axis) is a sub-light source that irradiates He-Ne laser light toward the half mirror 6. A barrel He-Ne laser device 8 is provided. A concave lens 7 is provided on the optical axis C connecting the center of the half mirror 6 and this He-Ne laser device 8, and once expands the luminous flux of the He-Ne laser beam from the He-Ne laser device 8,
The beam of this He-Ne laser beam is reflected by the half mirror 6, travels in the negative direction of two axes, passes through the objective lens 5 and the window hole 4a of the interference filter 4, and when it reaches the LD chip 3, the laser chip 3a is configured to converge on the front end surface of the

On the other hand, the half mirror 9 is provided on the optical axis A at an angle of 45° clockwise around the X-axis. This half mirror 9
A tungsten light bulb 11 attached to a socket 11a is located above (in the y-axis pressure direction). A convex lens 10 is provided on the optical axis B connecting the tungsten bulb 11 and the center of the half mirror 9, and the light beam from the tungsten bulb 11 is reflected by the half mirror 9 and travels in the negative direction. It plays the role of adjusting the spread of the luminous flux so that when it passes through the objective lens 5 and the interference filter 4 and reaches the LD tube 3, it is converged on the front end surface of the laser chip 3a.

The image signal of the TV camera 12 is processed by an image processing circuit (not shown). Based on the output of this image processing circuit, the vacuum chuck 2 moves slightly, and the position and orientation of the LD chip 3 are adjusted. Note that the image of the LD chip 3 is shown on a cathode ray tube (
(not shown) is monitored by the operator.

Next, the operation of this semiconductor element assembly apparatus 1 will be explained below.

First, the LD chip 3 is attracted to the vacuum chuck 2 and transported onto the optical axis A. Laser chip 3 of this LD chip 3
A tungsten light bulb 11 and a He-N
Each light beam from the e-laser device 8 is converged.

With the light beam from the tungsten bulb 11, the laser chip 3a
The light beam reflected from the front end surface passes through the interference filter 4 (excluding wavelength components around 0.633 μm), is captured by the entire effective diameter of the objective lens 5, and enters the TV camera 12.

On the other hand, H e-Ne reflected from the front end surface of the laser chip 3a
Of the light flux of the laser device 8, only that which passes through the window hole 4a of the interference filter 4 is captured by the objective lens 5 and is incident on the TV camera 12. Therefore, the numerical aperture NA2 of the objective lens 5 with respect to the luminous flux of the He-Ne laser beam is equal to the numerical aperture NA2 of the objective lens 5 with respect to the luminous flux of the tungsten bulb 11.
It is smaller than 1 (NA 2 < NA 1 ).

The image processing circuit processes the image signal of the 'rv camera 12 and determines the X and Y coordinates of the LD chip 3 depending on where the image of the laser chip 3a is located within the field of view of the TV left camera 2. At the same time, two coordinates are determined based on the contrast of the image of the laser chip 3a, and based on this result, the vacuum chuck 2 is slightly moved to adjust the position of the LD chip 3 so that it is accurately located on the optical axis A. .

Furthermore, the vacuum chuck 2 rotates the LD chip 3 around the X axis.
Determine the attitude of the LD chip 3 by tilting it around the X-axis so that the image of the laser beam knob 3a becomes the brightest. In this attitude, the front end surface of the laser chip 3a, that is, the inter-fold surface of the laser chip 3a is perpendicular to the optical axis A. At this time, He
Since the numerical aperture NA2 of the objective lens 5 with respect to the -Ne laser beam is small, the difference in brightness of the image of the laser chip 3a appears markedly, and the attitude of the LD chip 3 can be easily adjusted.

The LD chip 3 whose posture and position have been adjusted is conveyed onto the post 14 of the stem 13 fixed to a jig (not shown) while maintaining its posture and positional relationship, and is screwed onto the top surface of the post 14 with a screw material such as indium. Bonded. In FIG. 1, 15a115b and 15c are terminal bars.

In the above embodiment, the interference filter 4 is placed between the LD chip 3 and the objective lens 5, but it may also be placed between the objective lens 5 and the TV left camera 2, and can be changed as appropriate. Any optical system can be used, such as not only a convex lens but also an objective lens or a concave mirror that is a combination of multiple lenses.

In addition, in the above embodiment, He-Ne is used as the sub-light source.
Although a laser device is used, other light sources with a limited wavelength range, such as other laser devices or sodium lamps, can be used as appropriate.

(G) Effects of the Invention In the semiconductor device assembly apparatus of the present invention, emitted light travels on an optical axis connecting the semiconductor chip and the imaging means, and a sub-light source that irradiates the semiconductor chip and a sub-light source provided on the optical axis are provided. , is provided with a filter that transmits the light from the auxiliary light source reflected from the semiconductor chip only in a predetermined area around the optical axis, so for position detection of the semiconductor chip, the numerical aperture N of the objective optical system is
At the same time as increasing the AI, the numerical aperture NA2 of the objective optical system can be made small for detecting the attitude of the semiconductor chip, making it possible to maintain both position detection sensitivity and attitude detection sensitivity at a high level. It has the advantage that it can be bonded at an accurate position and posture.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining problems in a semiconductor element assembly apparatus according to an embodiment of the present invention. 2: Vacuum chuck, 3: LD (laser diode) chip, 4: Interference filter, 5: Objective lens, 8: He-Ne laser device, 11: Evening7guste7 electric r12: TV camera,
A: Optical axis. Patent applicant ROHM Co., Ltd. agent
Patent Attorney Shigeru Nakamura 2nd Ward

Claims (1)

[Claims] (1) A main light source that illuminates a semiconductor chip, an imaging device that captures an image of the semiconductor chip, and an optical axis that connects the semiconductor chip and the imaging device, and forms an image of the semiconductor chip on the imaging device. an objective optical system for processing an image signal from the imaging means; and an objective optical system for processing an image signal from the image pickup means, and supporting the semiconductor chip while adjusting the posture and position of the semiconductor chip in response to the image processing means, In a semiconductor device assembly apparatus comprising a semiconductor chip supporting and transporting means for transporting a semiconductor chip to a location, a sub-light source whose emitted light travels on the optical axis and irradiates the semiconductor chip; 1. A semiconductor device assembly apparatus comprising a filter that transmits light from an auxiliary light source reflected from a semiconductor chip only in a predetermined area around an optical axis.