JP2004363143A - Die bonding method of electronic component and optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die bonder capable of mounting two electronic components while keeping the relative position thereof through a simple arrangement. <P>SOLUTION: An optical pickup device comprises an optical system consisting of an objective lens, a mirror and a lens for condensing laser light at an object, and a base 3 for mounting a semiconductor laser chip 1 irradiating laser light, and a photodetector chip 2 for receiving the laser light. Surfaces 10a and 10b for mounting the semiconductor laser chip 1 and the photodetector chip 2, respectively, are provided on the base 3 of the optical pickup device, and protrusions 11 and 12 are provided in the vicinity of respective chip mounting surfaces 10a and 10b by previously setting the relative position of the semiconductor laser chip 1 and the photodetector chip 2. These semiconductor laser chip 1 and the photodetector chip 2 are abutted against the protrusions 11 and 12, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a die bonding method for an electronic component and an optical pickup device. More specifically, the present invention relates to a mounting technique that enables mounting with a simple method while maintaining a high positional relationship between two electronic components without performing advanced adjustment using image processing or the like.
[0002]
[Prior art]
For example, when manufacturing an optical pickup device, the relative positional relationship between the semiconductor laser chip and the photodetector chip is very important, and advanced mounting technology for positioning these relative positions with high precision and die bonding to the base is required. Is done.
[0003]
FIG. 5 is a flowchart showing an example of a conventional die bonding method, and FIG. 6 is an apparatus configuration diagram showing an example of a die bonding apparatus used in the die bonding method.
[0004]
As shown in FIG. 6, the die bonding apparatus includes a first mounting machine 101 on the alignment side that adjusts the position of the semiconductor chip before mounting it on the base, and a second mounting machine 101 on the mount side that mounts the semiconductor chip whose position has been adjusted on the base. It comprises a two-mounting machine 102 and a vacuum head 103 that moves between the alignment side and the mount side and that can move up and down.
[0005]
The first mounting machine 101 includes an XYθ stage 104 movable in the X and Y directions and rotatable in an in-plane direction (horizontal direction), a chip set unit 105 disposed on the XYθ stage 104, and a chip The first CCD camera 107 captures an image of the mounting state of the semiconductor laser chip or the semiconductor chip 106 that is a photodetector chip mounted on the setting unit 105.
[0006]
The second mounting machine 102 has substantially the same configuration, and includes an XYθ stage 108 movable in the X and Y directions and rotatable in the in-plane direction, a base 109 disposed on the XYθ stage 108, And a second CCD camera 111 for photographing the mounting state of the semiconductor chip 106 placed on the silver paste 110 applied to the chip mounting surface 109.
[0007]
The vacuum head 103 moves between the first mounter 101 on the alignment side and the second mounter 102 on the mount side, and is vertically movable. The vacuum head 103 sucks and holds the semiconductor chip 106 on the tip end surface thereof by vacuum suction, places the semiconductor chip 106 on the mounting surface of the chip set portion 105, and sucks the positioned semiconductor chip 106 again to mount it. And the semiconductor chip 106 is placed on the chip mounting surface of the base 109. When the positioning of the semiconductor chip 106 is completed, the vacuum head 103 operates so as to suck the base 109 and transfer it to the curing step.
[0008]
In order to mount a semiconductor laser chip and a photodetector chip at a predetermined relative position on the same base 109 using the above-described die bonding apparatus, as shown in the flowchart of FIG. The base 109 is set on the XYθ stage 108 of the machine 102. Next, in the step S2, the base 109 is positioned by the XYθ stage 108 so as to be in a predetermined state.
[0009]
Next, in step S3, a silver paste 110 is applied on the chip mounting surface of the base 109 on which the semiconductor chip 106 is mounted. Subsequently, in the process of step S4, a semiconductor chip 106, for example, a semiconductor laser chip (indicated as chip 1 in FIG. 5) is mounted on the chip setting section 105 of the first mounting machine 101. In the next step S5, the mounting position of the semiconductor chip 106 with respect to the chip set portion 105 is photographed by the first CCD camera 107, and the semiconductor chip 106 is brought into a predetermined state while checking the mounting position on a monitor. Is performed using the XYθ stage 104 as described above.
[0010]
Next, in the step S6, the semiconductor chip 106 whose positioning has been completed is sucked and held by the vacuum head 103. In the next step S7, after the semiconductor chip 106 sucked and held by the vacuum head 103 is transferred to the mount side, the mounting position of the semiconductor chip 106 with respect to the chip mounting surface is photographed by the second CCD camera 111, and the mounting is performed. The position is determined using the XYθ stage 108 so that the semiconductor chip 106 is in a predetermined state while checking the position on a monitor.
[0011]
Next, in the step S8, the vacuum head 103 sucks the base 109 from the XYθ stage 108, and transfers the base 109 to the curing step. Then, in step S9, the silver paste 110 of the base 109 taken out is heat-treated to fix the semiconductor chip 106 to the chip mounting surface of the base 109.
[0012]
Next, in step S10, the bay 109 on which the semiconductor laser chip is mounted is set again on the XYθ stage 108 of the second mounting machine 102. In the next step S11, the base 109 is positioned by the XYθ stage 108 with the semiconductor chip 106 mounted on the base 109 as a reference so as to be in a predetermined state.
[0013]
Next, in step S12, a silver paste 110 is applied on the chip mounting surface of the base 109 on which the semiconductor chip 106 is mounted. Subsequently, in step S13, the semiconductor chip 106, which is a photodetector chip (denoted as chip 2 in FIG. 5), is mounted on the chip set section 105. In the next step S14, the mounting position of the semiconductor chip 106 with respect to the chip setting section 105 is photographed by the first CCD camera 107, and the semiconductor chip 106 is brought into a predetermined state while checking the mounting position on a monitor. Is performed using the XYθ stage 104 as described above.
[0014]
Next, in the step S15, the semiconductor chip 106 whose positioning has been completed is sucked and held by the vacuum head 103. Then, in the next step S16, after the semiconductor chip 106 sucked and held by the vacuum head 103 is transferred to the mount side, the mounting position of the semiconductor chip 106 with respect to the chip mounting surface is photographed by the second CCD camera 111, and the mounting is performed. While confirming the position on the monitor, the XYθ stage 108 positions the semiconductor chip 106 so as to be at a predetermined relative position with respect to the previously mounted semiconductor chip 106.
[0015]
Next, in the process of step S17, the base 109 is sucked from the XYθ stage 108 by the vacuum head 103, and the base 109 is transferred to the curing process. Then, in step S18, the silver paste 110 on the base 109 taken out is heat-treated to fix the semiconductor chip 106 to the chip mounting surface of the base 109. This completes the die bonding to the base 109 of the two semiconductor chips 106, the semiconductor laser chip and the photodetector chip.
[0016]
In addition, although it is not a technology for mounting a semiconductor chip component constituting an optical pickup device, when mounting a laser diode on a copper mount material (heat sink), the edges of the laser diode and the copper mount material are respectively separated by two CCD cameras. There is also known a mounting technique for detecting a relative displacement between the laser diode and the copper mount material while photographing, and correcting the detected displacement by rotating a rotary table on which the laser diode and the copper mount material are mounted ( For example, see Patent Document 1).
[0017]
However, when the semiconductor chip 106 is mounted on the chip mounting surface while displaying images using a CCD camera, a complicated and expensive image processing system, a high-precision positioning mechanism, and a high-precision transfer mechanism are required. It becomes a die bonding device. In addition, operation, maintenance, and management of the die bonding apparatus are troublesome.
[0018]
In particular, when the semiconductor chip 106 is mounted in each step shown in the flowchart of FIG. 5, since the die bonding steps of the semiconductor laser chip and the photodetector chip are separated, the bonding of the silver paste 110 or the like is performed after each die bonding step. It is necessary to cure the agent in a constant temperature bath, leading to a longer lead time and a longer working time due to an increase in each step.
[0019]
Therefore, as a conventional mounting technique, for example, when mounting a wafer chip on a lead frame, in a process before mounting the wafer chip on the lead frame, a square opening was formed on a stage on which the wafer chip was transferred. A position shift correction claw is provided movably back and forth, left and right, and after vacuuming from a suction hole formed in the stage to hold the wafer chip on this stage, the position shift correction claw is moved to the corner of the wafer chip to move the position. There is known a technique in which corners of openings are brought into contact with each other and the position shift correction claw is moved until the center of a wafer chip placed on a stage and the center of a wafer chip at a target position coincide with each other.
[0020]
According to this method, an expensive image processing system, a high-precision positioning mechanism, and a high-precision transfer mechanism are not required, and the wafer chips can be positioned with a relatively simple apparatus configuration.
[0021]
[Patent Document 1]
JP 2001-24007 A (pages 4 and 5, FIGS. 1 and 3)
[Patent Document 2]
JP-A-11-330796 (pages 3 and 4, FIGS. 1, 3 and 6)
[0022]
[Problems to be solved by the invention]
However, in the mounting technique using the above-described position shift correction claw, since the positioned wafer chip needs to be carried to the next process and mounted again on the lead frame, there is a possibility that the position of the wafer chip is slightly shifted during transfer. is there. Further, in this mounting technique, since a wafer chip is not mounted directly on a lead frame, the number of mounting steps increases and the lead time becomes longer.
[0023]
Therefore, the present invention has been made in view of such a problem, and is implemented in a state in which the relative positions of two electronic components are held with high accuracy with a simple device configuration without using an expensive image processing system. Provided is a die bonding method for an electronic component, which can perform the curing step after mounting the electronic component in one time, and can reduce the lead time, and an optical pickup device manufactured by the method. The purpose is to do.
[0024]
[Means for Solving the Problems]
The electronic component die bonding method according to the present invention includes a mounting surface on which at least two electronic components are mounted at respective positions, and an abutting projection that preliminarily shows the relative positions of the two electronic components in the vicinity of each mounting surface. Applying a bonding paste for fixing the electronic component to each of the mounting surfaces on the mounting portion having: and abutting each of the electronic components mounted on the mounting surface against a respective abutting projection. Positioning the relative positions of these two electronic components.
[0025]
According to the electronic component die bonding method of the present invention, the abutting projections, which previously show the relative positions of the two electronic components, are provided in the vicinity of each mounting surface on which the electronic component formed on the mounting portion is mounted. Since the positioning is performed by abutting the electronic component against the abutting projection, the relative position of the two electronic components is naturally determined simply by abutting the electronic component against the abutting projection.
[0026]
Further, the optical pickup device of the present invention has a mounting surface on which the laser light emitting element and the light receiving element are mounted on a base on which the laser light emitting element and the light receiving element are mounted, and the laser light emitting element and the light receiving It is characterized in that the laser light emitting element and the light receiving element are abutted against the respective abutting projections.
[0027]
According to the optical pickup device of the present invention, the base itself is provided with the abutting projections that indicate the relative positions of the laser light emitting element and the light receiving element in advance, and the laser emitting element and the light receiving element abut against the respective abutting projections. The laser light emitting element and the light receiving element are directly mounted on the base at predetermined relative positions. Therefore, it is possible to reduce the troublesome process of mounting the two laser light emitting elements and the light receiving element on the base after positioning the relative positions of the laser light emitting element and the light receiving element in advance.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. This embodiment is a die bonding method that constitutes an optical pickup device, and enables a relative position between a semiconductor laser chip and a photodetector chip, which are two electronic components, to be mounted on a base with a high accuracy and a simple method and structure. The present invention is applied to an optical pickup device manufactured by using the method.
[0029]
"Configuration of optical pickup device"
First, the configuration of the optical pickup device will be described with reference to the drawings. FIG. 1 is a schematic plan view of the optical pickup device, and FIG. 2 is a schematic side view of the optical pickup device.
[0030]
As shown in FIG. 2, the optical pickup device is a chip mounting base on which a semiconductor laser chip 1 which is a laser light emitting element for irradiating laser light Hv and a photodetector chip 2 which is a light receiving element for receiving laser light Hv are mounted. The optical system includes a base 3 and an optical system 5 for irradiating a laser beam Hv emitted from the semiconductor laser chip 1 to an optical disc 4 as a target portion, and causing reflected light from the optical disc 4 to enter the photodetector chip 2. .
[0031]
As shown in FIG. 2, the optical system 5 includes an objective lens 6 for condensing the laser beam Hv emitted from the semiconductor laser chip 1 on the optical disc 4 as an object, a mirror 7 for bending the laser beam Hv, and an optical disc. An optical element (lens) 8 that bends the reflected light from the photodetector 4 to the photodetector chip 2.
[0032]
In the optical system 5, the laser beam Hv emitted from the semiconductor laser chip 1 passes through the optical element 8, changes its direction to the objective lens 6 by the mirror 7, and then irradiates the signal recording layer of the optical disc 4. Is done. Then, the reflected light of the laser light Hv from the signal recording layer is redirected by the mirror 7 via the objective lens 6 again, and is incident on the photodetector chip 2 by the optical element 8.
[0033]
As shown in FIG. 1, the base 3 is provided with a semiconductor laser chip 1, a photodetector chip 2, and a lead frame 9 for mounting these directly on the base 3. Since the relative positions of the semiconductor laser chip 1 and the photodetector chip 2 are very important and greatly affect the signal reading output, the semiconductor laser chip 1 and the photodetector chip 2 need to be mounted on the base 3 with high accuracy.
[0034]
As shown in FIGS. 1 and 2, the semiconductor laser chip 1 and the photodetector chip 2 are fixed by applying and curing a silver paste as a bonding paste on each of the chip mounting surfaces 10a and 10b of the base 3. In the vicinity of each of the chip mounting surfaces 10a and 10b, abutting projections 11 and 12 are formed to abut the semiconductor laser chip 1 and the photodetector chip 2 and to position them as predetermined relative positions. .
[0035]
These abutting protrusions 11 and 12 are abutting portions 11A extending in the same X direction as the traveling direction of the laser beam Hv irradiated from the semiconductor laser chip 1 toward the mirror 7 and in the Y direction orthogonal to the X direction. , 11B, 12A, and 12B are formed as planar substantially inverted L-shaped blocks. Each of the abutting portions 11A, 11B, 12A, and 12B has an abutting surface 11a, 11b that comes into surface contact with two side surfaces sandwiching one corner 1a, 2a of the semiconductor laser chip 1 and the photodetector chip 2, respectively. 12a and 12b are formed.
[0036]
The inner corners, which are the intersections of the abutting portions 11A and 12A extending in the X direction and the abutting portions 11B and 12B extending in the Y direction, are provided on the abutting projections 11 and 12, respectively. Relief portions 13 and 14 are formed so that the semiconductor laser chip 1 and the photodetector chip 2 are brought into non-contact with the corner portions of the photodetector chip 2 and the semiconductor laser chip 1 to surely contact the abutting portions 11A, 11B, 12A and 12B. ing.
[0037]
When the semiconductor laser chip 1 and the photodetector chip 2 abut against the respective abutting portions 11A, 11B, 12A, and 12B, the abutting projections 11 and 12 form the semiconductor laser chip 1 and the photodetector chip 2, respectively. The center is arranged on the base 3 so that the respective positions in the X direction, the Y direction, and the θ direction (the direction of horizontal rotation in the in-plane direction) and the height position have a predetermined positional relationship. I have.
[0038]
The abutting projection 11 against which the semiconductor laser chip 1 abuts and the abutting projection 12 against which the photodetector chip 2 abuts are arranged with extremely high dimensional accuracy of ± 20 μm in the X and Y directions. I have.
[0039]
Therefore, the semiconductor laser chip 1 and the photodetector chip 2 are fixed to each of the chip mounting surfaces 10a and 10b in a state where the semiconductor laser chip 1 and the photodetector chip 2 abut against these butting protrusions 11 and 12, respectively. Since the relative positions of the semiconductor laser chip 1 and the photodetector chip 2 are in a highly accurate positional relationship, a highly accurate output signal can be obtained by the photodetector chip 2. In addition, since the semiconductor laser chip 1 and the photodetector chip 2 are directly fixed to the base 3 in a state where the semiconductor laser chip 1 and the photodetector chip 2 are abutted against the abutting projections 11 and 12, respectively, the semiconductor laser chip 1 and the photodetector chip 2 have high mechanical strength. It becomes.
[0040]
"Die bonding method"
Next, the die bonding method of the present embodiment will be described with reference to the drawings. FIG. 3 is a flowchart showing a process of mounting the semiconductor laser chip 1 and the photodetector chip 2 on the base 3. FIG. 4 is a flowchart showing the process of mounting the semiconductor laser chip 1 and the photodetector chip 2 on the abutting projections 11 and 12 provided on the base 3. It is a figure which shows a process of hitting.
[0041]
As shown in the flowchart of FIG. 3, first, in step 51, the base 3 is set on the base mounting portion 15. Next, in step 52, a silver paste 16 for fixing the semiconductor laser chip 1 and the photodetector chip 2 is applied and applied to each of the chip mounting surfaces 10a and 10b on the base 3.
[0042]
Next, in the process of step S53, as shown in FIG. 4B, the semiconductor laser chip 1 (denoted as chip 1 in FIG. 3) is mounted on the chip mounting surface 10a with tweezers 17, and then, The two side surfaces sandwiching one corner of the semiconductor laser chip 1 are brought into surface contact with the abutting portions 11A and 11B extending in the X and Y directions, respectively, protruding near the chip mounting surface 10a using tweezers 17. I will hit you. For example, as shown in FIG. 4A, the semiconductor laser chip 1 is pressed by the tweezers 17 with a predetermined urging force F against the respective abutting portions 11A and 11B.
[0043]
Next, when the setting and positioning of the semiconductor laser chip 1 are completed, in the next step S54, the photodetector chip 2 (indicated as chip 2 in FIG. 3) is similarly pinched by the tweezers 17 and the chip mounting surface is set. 10b. Then, using tweezers 17, two side surfaces sandwiching one corner of the photodetector chip 2 are respectively abutted against abutting portions 12 </ b> A and 12 </ b> B extending in the X direction and the Y direction protruding near the chip mounting surface 10 b. Hit it.
[0044]
As a result, the semiconductor laser chip 1 and the photodetector chip 2 abutted on the respective abutting projections 11 and 12 are naturally mounted on the base 3 at predetermined relative positions.
[0045]
Next, in the step S55, the base 3 on which the semiconductor laser chip 1 and the photodetector chip 2 are mounted is taken out from the base mounting portion 15, and the base 3 is transferred to a curing step. Then, in step S56, the semiconductor laser chip 1 and the photodetector chip 2 are fixed to the chip mounting surfaces 10a and 10b by heat-treating the silver paste 16 of the base 3 taken out in a thermostat.
[0046]
As described above, according to the die bonding method of the present embodiment, the relative positions of the two semiconductor chips, the semiconductor laser chip 1 and the photodetector chip 2, whose relative positions are controlled very strictly, are determined in advance. By simply mounting the semiconductor chip on the base 3 having the abutting projections 11 and 12, the relative position of these two semiconductor chips can be made highly accurate by itself. No mechanism or high-precision transfer mechanism is required.
[0047]
Further, in the die bonding method of the present embodiment, since the semiconductor laser chip 1 and the photodetector chip 2 are cured at the same time, the lead time can be greatly reduced and the manufacturing process can be greatly simplified. it can.
[0048]
As described above, the specific embodiments to which the present invention is applied have been described. However, the present invention is not limited to the above-described embodiments, and can be variously modified.
[0049]
In the above embodiment, the semiconductor laser chip 1 and the photodetector chip 2 are separately mounted on the chip mounting surfaces 10a and 10b using tweezers 17, respectively. 1 and the photodetector chip 2 may be simultaneously mounted on each of the chip mounting surfaces 10a and 10b to perform positioning. By doing so, the process of mounting the semiconductor chip on the base 3 can be further simplified, and the manufacturing time can be greatly reduced.
[0050]
【The invention's effect】
According to the electronic component die bonding method of the present invention, an abutting projection that preliminarily indicates the relative position of the two electronic components is provided in the vicinity of each mounting surface, and the electronic component is simply abutted against the abutting projection. Thus, the relative positions of these electronic components can be easily determined as high precision without using an expensive image processing system, high-precision positioning mechanism, or high-precision transfer mechanism.
[0051]
Further, according to the die bonding method of the present invention, only one curing step is required after mounting two electronic components, so that the lead time can be greatly reduced and the number of manufacturing steps can be reduced. In addition, a chip such as a semiconductor laser chip that does not need to be subjected to thermal cycles many times can be cured only once, so that the performance of the electronic component is not impaired.
[0052]
According to the optical pickup device of the present invention, the base itself is provided with the abutting projections that indicate the relative positions of the laser light emitting element and the light receiving element in advance, and the laser emitting element and the light receiving element abut against the respective abutting projections. Since it is mounted by mounting, a special device such as an expensive image processing system is not required, and the relative position can be maintained with high accuracy. This can reduce capital investment, processing cost, maintenance cost, and equipment installation space.
[Brief description of the drawings]
FIG.
FIG. 1 is a schematic plan view of an optical pickup device to which the present invention is applied.
FIG. 2 is a schematic side view of an optical pickup device to which the present invention is applied.
FIG. 3 is a flowchart showing a process of mounting the semiconductor laser chip and the photodetector chip on a base;
FIGS. 4A and 4B show a process of abutting a semiconductor laser chip and a photodetector chip on an abutting projection provided on a base, wherein FIG. 4A is a plan view of a chip mounting portion, and FIG. FIG.
FIG. 5 is a flowchart showing an example of a conventional die bonding method.
FIG. 6 is an apparatus configuration diagram showing an example of a die bonding apparatus used in a conventional die bonding method.
[Explanation of symbols]
1. Semiconductor laser chip (laser light emitting element)
2. Photodetector chip (light receiving element)
DESCRIPTION OF SYMBOLS 3 ... Base 5 ... Optical system 6 ... Objective lens 8 ... Optical element 9 ... Lead frames 10a, 10b ... Chip mounting surfaces 11, 12 ... Butt projections 11A, 11B, 12A, 12B ... Butt 16 ... Silver paste

Claims (4)

The mounting surface having at least two electronic components mounted at their respective positions, and a mounting portion having an abutting projection that previously shows the relative position of the two electronic components in the vicinity of each mounting surface, Applying a bonding paste for fixing the electronic component to a mounting surface,
Placing the electronic components on their respective mounting surfaces,
A step of abutting the respective electronic components against the respective abutting projections to determine the relative positions of the two electronic components;
A step of curing the bonding paste. A method of die bonding an electronic component according to claim 1,
The two electronic parts are a laser light emitting element that irradiates laser light and a light receiving element that receives laser light, and the attached part is a base of an optical pickup provided with a lead frame. Die bonding method. An optical pickup device including an objective lens that focuses laser light on an object, an optical system including a mirror and a lens, and a laser light emitting element that emits laser light and a base on which a light receiving element that receives laser light is mounted. ,
The base is provided with a mounting surface on which the laser light-emitting element and the light-receiving element are mounted, and an abutting protruding portion in which the relative positions of the laser light-emitting element and the light-receiving element are set in advance in the vicinity of each mounting surface. An optical pickup device comprising a light emitting element and a light receiving element abutting against respective abutting projections. The optical pickup device according to claim 3, wherein
The optical pickup device, wherein the abutting projection has an abutting surface that comes into surface contact with at least two side surfaces sandwiching one corner of the laser light emitting element and the light receiving element.

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