JP2000277540A - Part bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a part bonding device which is capable of very accurately bonding a part to a mounting object at a prescribed position without being affected by the thermal expansion of the mounting object and simplified in structure. SOLUTION: A part bonding device is equipped with a heater 20 which heats a heat sink 16, a bumper 22 which is made to bear against the reference edge face 16a of the heat sink 16 so as to position an LD chip 12 and whose thermal expansion coefficient is lower than that of the heat sink 16, and a spring 24 which bears against the edge face 16b of the heat sink 16 to press the heat sink 16 against the bumper 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component bonding apparatus for bonding a component to a predetermined position on a mounting object.

[0002]

2. Description of the Related Art For example, a semiconductor laser device (hereinafter, referred to as an LD)
Is generally used in a state of being bonded on a heat sink having good thermal conductivity in order to prevent internal heat generation during light emission and to prevent self-destruction caused by this heat. Specifically, as shown in FIG. 4, the LD 1 includes a heat sink 2 and the heat sink 2.
A semiconductor laser chip (hereinafter, referred to as an LD chip) 3 which is integrally coupled in a state of being stacked thereon.

At this time, in order to efficiently absorb the heat generated by the LD chip 3 and efficiently extract the generated laser light,
It is necessary to bond the LD chip 3 and the heat sink 2 so that the end faces thereof do not shift from each other (see FIG. 5). However, in the bonding, since the heat sink 2 on which the brazing material is deposited is generally heated by a heater (heating means) to braze the LD chip 3 and the heat sink 2, the heat sink fixing portion and its peripheral portion are bonded. Heat from the heater is transferred, and thermal deformation occurs in this portion.

As a result, the relative position between the LD chip 3 and the heat sink 2 positioned before the heating of the heater is shifted during bonding, causing a reduction in heat radiation and further shortening the life of the LD 1. Has been pointed out. In addition, the heater heating element itself and the heat sink 2
It is impossible to eliminate the influence of thermal expansion itself, and thermal deformation occurs in these parts, and in particular, it becomes impossible to position the LD chip 3 and the heat sink 2 with high precision on the order of μm. There's a problem.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 5-343502, the heat sink and the LD chip are heated and heated before bonding, and are positioned and bonded after thermal deformation is stabilized. Die bonding apparatuses are known.

[0006]

However, in the above prior art, since the brazing material is left in a high temperature liquid state for a long time, it is pointed out that the brazing material is easily oxidized and the adhesive strength is reduced. ing. Further, since the bonding is performed in a state where the brazing material is in a liquid state, the brazing material easily adheres to the side surface of the LD chip, that is, the light emitting surface, and the
May adversely affect the performance of the device. Furthermore, it is necessary to heat the heat sink and the peripheral members of the LD chip to the same temperature, which requires a long time for heating,
A large heater capacity is required.

SUMMARY OF THE INVENTION The present invention solves this kind of problem, and provides a highly accurate and efficient bonding of a component to a predetermined position on an object to be mounted, and a component that can be easily simplified in configuration. An object is to provide a bonding apparatus.

[0008]

In the component bonding apparatus according to the present invention, when the object to be mounted is heated by the heating means, the abutment member abuts on the reference end surface of the object to be mounted, while The reference end surface is held at a predetermined position by an elastic member abutting on the end surface of the object opposite to the reference surface.

Here, the abutment member is formed of a material having a lower coefficient of thermal expansion than the object to be mounted, for example, 5 × 10 ⁻⁶ or less. Therefore, the abutting member can be maintained at a predetermined position of the abutting end face without being affected by the heating means, and even if thermal deformation occurs in the mounting target, the mounting target can be mounted on the mounting target. The reference end surface can be reliably held at a predetermined position. This makes it possible to position and bond the component at a desired position on the mounting object with high accuracy.

Further, the abutting member has a lower thermal conductivity than the mounting object, and effectively prevents the heat of the mounting object from being dissipated from the abutting member. Therefore, the energy applied to the heating means is reduced, and the energy efficiency is easily improved. Further, a heat insulating layer is interposed between the supporting member provided with the abutting member and the heating means, and the supporting member is completely insulated from the heat by the heating means, and generates a thermal displacement of the reference end face. Is prevented as much as possible.

[0011]

FIG. 1 is a schematic perspective explanatory view of a component bonding apparatus 10 according to an embodiment of the present invention.
FIG. 2 is an explanatory side view of the bonding apparatus 10.

The bonding apparatus 10 includes a component LD
(Laser Diode) A component holding means 14 capable of holding and raising and lowering a chip 12 and a heat sink 16
-Y-θ stage 18, a heater 20 serving as a heating means for mounting and heating the heat sink 16, and a reference end surface 1a contacting a reference end surface 16a of the heat sink 16.
A spring (elastic member) which abuts against the abutting member 22 for holding the heat sink 6a at a predetermined position and an end surface 16b of the heat sink 16 opposite to the reference end surface 16a and presses the heat sink 16 against the abutting member 22 ) 24,
Imaging means 26 for imaging the LD chip 12 and the heat sink 16 from above the bonding position, and the LD chip 12 and the heat sink 16 based on the relative position information of the imaged LD chip 12 and the heat sink 16 Control means 27 for relatively correcting the position.

The XY-θ stage 18 is provided with a movable base 28 which can move in the X-axis direction and the Y-axis direction via driving means such as a ball screw (not shown).
A rotary table 30, which is a θ table rotatable around the Z axis, is disposed on the upper side. A support member 34 is disposed on the turntable 30, and the heat insulating layer 3 is provided on the support member 34.
2, the heater 20 is mounted. The butting member 22 is fixed to the upper end of the support member 34.

The abutment member 22 has a lower coefficient of thermal expansion than the heat sink 16 and is set to 5 × 10 ⁻⁶ or less, preferably 3 × 10 ⁻⁷ or less. Butt member 2
2 further has a lower thermal conductivity than the heat sink 16, and specifically, is set to 2 W / mK or less. In the present embodiment, the butting member 22 is made of LiO-A
l ₂ O ₃ is constituted by crystallized glass -SiO ₂ system, a thermal expansion coefficient of 2 × 10 ^-7, thermal conductivity of 2W / m
K is set. In the present embodiment, the heat insulating layer 32
The support member 34 is made of the same material as the butting member 22.

A holding plate 36 is provided on the end surface 16b side of the heat sink 16, and the spring 24 is interposed between the holding plate 36 and the end surface 16b. The heater 20 is provided with a suction hole 38 communicating with a vacuum source (not shown) for sucking and holding the heat sink 16 (see FIG. 2).

The component holding means 14 includes a frame 42 fixed to a column 40 and extending in the Z-axis direction. A motor 44 is fixed to an upper end of the frame 42. Motor 4
The ball screw 46 connected to the output shaft 4 and extending in the Z-axis direction is screwed to a nut member (not shown) provided on the Z-axis movable table 48. The pressing means 50 is fixed to the Z-axis movable table 48, and the holding member 52 is attached to the pressing means 50. The holding member 52 has a hollow shape, and the inside thereof communicates with a negative pressure source (not shown).

The image pickup means 26 is mounted on the upper part of the column 40 via a mount 54, and is provided with one or a plurality of CCs.
A D camera 56 and an optical lens system 58 are provided. FIG.
As shown in FIG. 5, the CCD camera 56 is connected to an image processing unit 60, which captures the images of the LD chip 12 and the heat sink 16 captured by the CCD camera 56 as image signals, and respectively. And has a function of calculating the amount of positional deviation. Image processing unit 60
Is connected to the control means 27.
Is based on the calculation result from the image processing unit 60.
It has a function of driving the Y-θ stage 18 to perform position correction.

The bonding apparatus 1 configured as described above
The operation of 0 will be described below.

First, the heat sink 16 is disposed on the heater 20, and the suction holes 38 provided in the heater 20 are provided.
The heat sink 16 is sucked and held on the heater 20 by sucking the heat. At this time, a reference end surface 16a of the heat sink 16 for positioning the LD chip 12 is in contact with the abutment member 22 to be positioned, and a spring 24 is in contact with the end surface 16b of the heat sink 16.

On the other hand, in the component holding means 14, the holding member 5
The LD chip 12 is sucked and held at the tip of the X.
The Y-θ stage 18 is driven via the control means 27. For this reason, the bonding position of the heat sink 16 is arranged on the optical axis of the imaging unit 26. Next, the motor 4
The Z-axis movable table 48 is lowered via the ball screw 46 under the action of the
The tip 12 descends and is arranged at a predetermined height position.

Here, the imaging means 26 is driven, and the LD chip 12 and the heat sink 16 are imaged. An image signal obtained by the CCD camera 56 constituting the imaging means 26 is sent to an image processing unit 60 and subjected to image processing.
The shift amount is calculated based on the relative position information between the LD chip 12 and the heat sink 16. This deviation amount is sent to the control means 27 and is sent to the LD chip 12 and the heat sink 16.
Is corrected in real time at regular time intervals.

For example, as shown in FIG.
When it is detected that the edge of No. 2 is shifted from the reference end face 16a of the heat sink 16 by the correction amount Δθ (> reference value), the rotation table 30 provided on the XY-θ stage 18 corrects the rotation. Rotate by an angle corresponding to the amount △ θ,
The shift amount is corrected. Next, when the shift amount in the X-axis direction and the Y-axis direction is larger than the reference value, XY-
stage 18 is driven and the feedback control is performed until the reference end face 16a of the heat sink 16 matches the edge position of the LD chip 12.

After the amount of deviation between the LD chip 12 and the heat sink 16 falls within the allowable range, the heater 20 is heated to a predetermined temperature, in this embodiment, 120 ° C. Then, the motor 44 is driven to lower the Z-axis movable table 48, and the LD chip 1 sucked and held by the holding member 52.
2 abuts on heat sink 16. Further, the heater 20 is heated to a predetermined temperature, in this embodiment, 200 ° C. in a state where the LD chip 12 is pressed and held on the heat sink 16 with a constant load via the pressing means 50. As a result, the brazing material previously provided on the upper surface of the heat sink 16 is melted, and is cooled after heating for a predetermined time, whereby the LD chip 12 is bonded onto the heat sink 16.

In this case, in this embodiment, the LD chip 1
In order to position the heat sink 2, abutment members 22 having a lower coefficient of thermal expansion than the heat sink 16 abut against a reference end surface 16a set on the heat sink 16, and a spring 24 is attached to an end surface 16b of the heat sink 16. The heat sink 16 is pressed against the abutting member 22 side in contact. For this reason, even if the heat sink 16 is thermally deformed when the heater 20 is driven to heat the heat sink 16, the position of the reference end surface 16 a of the heat sink 16 is reliably maintained by the butting member 22.

Thus, the relative position between the LD chip 12 and the heat sink 16 positioned before the heater 20 is heated does not shift during bonding, and the LD chip 12 can be bonded to a predetermined position with high precision. The effect that it can be obtained is obtained. In particular, when positioning the LD chip 12 and the heat sink 16 with high accuracy on the order of μm, the thermal expansion of the heater 20 itself and the heat sink 16
It is possible to reliably prevent the occurrence of displacement between the LD chip 12 and the heat sink 16 without being affected by the thermal expansion of itself.

In the present embodiment, the abutting member 22 has a thermal expansion coefficient of 2 × 10 ⁻⁷ and a thermal conductivity of 2 W / mK.
iO-Al ₂ O ₃ was used crystallized glass -SiO ₂ system, the amount of deviation of the LD chip 12 and the heat sink 16 becomes 1μm or less. On the other hand, when the abutment member 22 was not used, the displacement amount was 5 μm or more, and the use of the abutment member 22 resulted in a high-precision bonding operation.

In this embodiment, the heat sink 1
Since the brazing material No. 6 is not left in a liquid state at a high temperature for a long time, the brazing material is prevented from being oxidized and the adhesive strength is reduced. No deterioration of LD performance is caused by the adhesion of the material.

Further, in the present embodiment, the thermal conductivity of the butting member 22 is set to 2 W / mK or less.
Therefore, when the heat sink 16 is heated, the amount of heat radiation from the abutting member 22 that comes into contact with the heat sink 16 can be effectively reduced, and the energy applied to the heater 20 decreases, and the energy efficiency improves. The advantage is obtained.

Further, between the heater 20 and the supporting member 34, a heat insulating layer 32 made of the same material as the abutting member 22 is provided. Therefore, it is possible to reliably prevent the heat from the heater 20 from being transmitted to the support member 34, and it is possible to more reliably reduce the thermal displacement of the abutment member 22.

In the present embodiment, the LD chip 12 is used as a component and the heat sink 16 is used as a mounting object. However, for example, a semiconductor chip may be used as a component and a substrate may be used as a mounting object. The effect of is obtained. Further, the heat sink 16 is connected to the XY-
θ heat sink 16 and
Although it is configured to be movable in the axis, Y axis and θ axis directions,
The XY stage may be provided on the pressing means 50 for sucking and holding the LD chip 12, while the heat sink 16 may be mounted on the θ stage.

[0031]

In the component bonding apparatus according to the present invention, when the mounting object is heated via the heating means, the reference end face set on the mounting object for positioning the component has a low thermal expansion coefficient. Since the abutment member having the abutment abuts, even if the mounting object thermally expands, the reference end surface can be reliably held at a predetermined position, and the component can be bonded to the predetermined position with high precision. In particular, the configuration is effectively simplified, and the mounting object is not left in a heated state for a long time, and the oxidation of the brazing material is effectively prevented, so that a highly accurate bonding operation can be performed.

[Brief description of the drawings]

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

FIG. 2 is an explanatory side view of the bonding apparatus.

FIG. 3 is an explanatory diagram of an image pickup state by an image pickup unit constituting the bonding apparatus.

FIG. 4 is an explanatory perspective view of a general LD.

FIG. 5 is an explanatory side view when an LD chip constituting the LD and a heat sink are joined in a good state.

FIG. 6 is an explanatory side view when the LD chip and the heat sink are bonded in a shifted state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Bonding apparatus 12 ... LD chip 14 ... Component holding means 16 ... Heat sink 18 ... XY-.theta. Stage 22 ... Butting member 24 ... Spring 26 ... Imaging means 27 ... Control means 30 ... Rotary table 32 ... Heat insulation layer 34 ... Supporting member 48: Z-axis movable table 52: Holding member 56: CCD camera 58: Optical lens system 60: Image processing unit

Claims (4)

[Claims] 1. A component bonding apparatus for bonding a component to a predetermined position on a mounting target, comprising: a heating unit for heating the mounting target; and a mounting target for positioning the component. Abuts against the reference end surface set to hold the reference end surface at a predetermined position, and has a lower thermal expansion coefficient than the mounting object; and an abutting member opposite to the reference end surface of the mounting object. And a resilient member that abuts against the end face of (a) and presses the mounting object against the abutting member. 2. The component bonding apparatus according to claim 1, wherein the abutting member has a lower thermal conductivity than the mounting object. 3. The bonding apparatus according to claim 1, wherein a heat insulating layer is interposed between the supporting member provided with the abutting member and the heating means. Bonding equipment. 4. A bonding apparatus according to claim 1, wherein said component holding means is capable of holding said component and moving up and down; an imaging means for imaging said component and said mounting object from above a bonding position; Control means for relatively correcting the position of the component and the object to be mounted based on the relative position information of the component and the object to be mounted.