JP2007080964A - Die bonding apparatus of semiconductor laser element and method of die bonding of semiconductor laser element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die bonding apparatus of semiconductor laser element to conduct die bonding through high precision positioning of semiconductor laser element with a simplified and compact structure. <P>SOLUTION: The die bonding apparatus 20 for die-bonding a semiconductor laser element 26 to a step by adjusting the axial direction of the light emitted from the semiconductor laser element 26 comprises a CCD (Charge-Coupled Device) camera 21 for measuring position of the light emitting point of the semiconductor laser element 26, a first light receiving element 22 for measuring optical output by receiving the radiated light, and a second light receiving element 23 for receiving the radiated light via a slit 49 and measuring the peak location of the maximum optical output. The first light receiving element 22 and the second light receiving element 23 constitute an integrated member through loading together to a supporting arm member 44. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor laser element die bonding apparatus and a die bonding method.

  For example, a semiconductor laser device used as a light source such as an apparatus for recording / reproducing information with respect to an optical recording medium is manufactured by die-bonding a semiconductor laser element that emits laser light to a stem. In general, light emitted from a semiconductor laser element has an emission angle that is a spread angle. For example, when a semiconductor laser device is used as a light source of an optical information recording / reproducing apparatus, it is preferable to use light having a high output intensity for recording / reproducing information. Therefore, the semiconductor laser element outputs light emitted from the semiconductor laser element. The optical axis portion, which is the peak position where the intensity is maximum, is positioned so as to be incident on the optical system and die-bonded to the stem.

  Conventionally, as a positioning means for bonding a semiconductor laser element to a stem, a method of detecting the outer shape of the semiconductor laser element and performing positioning based on the outer shape has been adopted. FIG. 9 is a diagram showing a light emission state of the semiconductor laser element. The semiconductor laser element 1 usually emits light from the two opposite surfaces 2 and 3, and is emitted from one surface 2 by adjusting the light reflectance and light transmittance of the two surfaces 2 and 3, respectively. The light output is configured to be larger than the light output emitted from the other surface 3. Light emitted from one surface 2 having a large output is used for recording and reproducing information, and light emitted from the other surface 3 having a small output is used for an optical output monitor of the semiconductor laser device 1 and the like. The semiconductor laser element 1 emits light from both the one surface 2 and the other surface 3, but here, the one surface 2 that emits light that has a large output and is used for recording and reproducing information is defined as a light emitting surface. I will call it.

  When positioning is performed based on the outer shape of the semiconductor laser element 1, for example, the central portion of the side of the light emitting surface 2 on the top view is the light emitting point 4, and the direction perpendicular to the light emitting surface 2 through the light emitting point 4 is the virtual light. Positioning is performed with the axis 5 defined. However, as shown in FIG. 9, in the semiconductor laser element 1, the true optical axis 7 of the light 6 emitted from the light emitting surface 2 is not necessarily perpendicular to the light emitting surface 2. That is, the true optical axis 7 does not coincide with the virtual optical axis 5 obtained from the outer shape. Therefore, if positioning is performed based on the outer shape of the semiconductor laser element 1, there is a problem that a decrease in accuracy is induced. In addition, when the semiconductor laser element 1 is cracked, chipped, soiled, or the like, the detected outer shape becomes distorted, which may further deteriorate the positioning accuracy.

  Further, as a conventional method used for positioning of the semiconductor laser element 1, laser light is emitted at an arbitrary output, and the brightness value of the image data of the optical image device is not saturated by an optical image device such as a CCD camera. The light emission near-field image and the far-field image are taken, and the light emission point position and the radiation angle are determined from the shift of the center of gravity, and positioning is performed (for example, see Patent Documents 1 to 3).

  FIG. 10 is a diagram showing the difference in the light emission pattern accompanying the difference in the light emission output of the semiconductor laser element 1. In the semiconductor laser element 1, as shown in FIG. 10, a phenomenon called radiation angle transition (beam shift) due to a difference in light emission output occurs. That is, since the radiation angle changes with the change in the light emission output, in order to improve the positioning accuracy, the semiconductor laser element 1 is caused to emit light with an output close to the actual use output, and from the radiation angle at the output close to the actual use. It is required to adjust so that the obtained optical axis is in a predetermined direction.

  However, as the information processing speed increases, the light output for actual use required for the semiconductor laser element 1 increases. Therefore, if the light output close to actual use is directly input to the light receiving element such as a CCD, the light receiving element. Will be saturated. FIG. 11 is a diagram showing a far-field image and luminance distribution of the semiconductor laser element 1 input to the light receiving element. FIG. 11A shows a far-field image, and an output saturation region 8 is formed near the center. A line 9 in FIG. 11B shows a luminance distribution across the far-field image, and the line 9 is flat in a portion corresponding to the output saturation region 8 and the output is saturated.

  Further, since the semiconductor laser device 1 emits light in a state of poor heat dissipation before being mounted on the stem at the time of positioning, the duty is small (light emission time is 1 of the pulse period) in order to suppress the heat generation temperature rise due to light emission. It is necessary to perform pulse driving. When the semiconductor laser device 1 emits pulses, the pulsed light is taken into the light receiving device using a mechanical or electronic shutter to prevent unnecessary light from entering the light receiving device.

  FIG. 12 is a timing chart showing pulse emission timing and shutter opening timing. In FIG. 12, the line 10 indicates the pulsed light emitted from the semiconductor laser element 1, and the line 11 indicates the timing when the shutter is opened. The rising portions of both lines 10 and 11 indicate light emission and release. As shown in FIG. 12, when the shutter opening time is shortened in accordance with pulse driving with a small duty, the duty does not match and light enters as shown in FIG. 12 (a), or as shown in FIG. 12 (b). Thus, there is a problem that accurate light emission measurement cannot be performed due to the absence of light.

  Instead of causing the semiconductor laser element 1 to emit light continuously, an ND filter (attenuation filter) may be placed in the optical path so that excessive light does not enter the light receiving element. However, when an attenuation filter is inserted, the output intensity distribution of the radiated light of the semiconductor laser device 1 changes, so that there is a problem that a correct optical axis cannot be measured.

  In order to incorporate the positioning device into the die-bonding device, it is desirable that the positioning device is small. Conventionally, in a semiconductor laser element die-bonding apparatus, since the semiconductor laser element is positioned and bonded to the stem and then passed through the final inspection process, the quality of the semiconductor laser element cannot be determined. When the element is defective, there is a member loss due to execution up to bonding and a reduction in work efficiency due to waste of work processes.

JP-A-7-43112 JP 2003-188451 A JP 2005-5613 A

  An object of the present invention is to provide a die-bonding apparatus and a die-bonding method for a semiconductor laser element that can position and die-bond a semiconductor laser element with high accuracy with a simple and compact configuration.

The present invention relates to a die bonding apparatus for a semiconductor laser element that adjusts the direction of the optical axis that is the axis of light emitted from the semiconductor laser element and die-bonds the semiconductor laser element to the stem.
A light emitting point position measuring means for measuring a position of a light emitting point which is a position where light is emitted from the semiconductor laser element;
A first light receiving element that receives light emitted from the semiconductor laser element and measures a light output;
A second light receiving element that receives light emitted from the semiconductor laser element through a slit and measures a peak position at which the light output is maximized;
The first light receiving element and the second light receiving element constitute an integral member, which is a die bonding apparatus for a semiconductor laser element.

  In addition, the present invention includes a light receiving element driving unit that moves the first light receiving element and the second light receiving element that are integrally formed in a direction perpendicular to the optical axis.

  In the invention, it is preferable that the first light receiving element is arranged such that a light receiving surface that receives light emitted from the semiconductor laser element has an inclination angle with respect to a perpendicular to the optical axis.

  In addition, the present invention includes a light receiving element signal adjusting unit that variably adjusts the intensity of signals output from the first light receiving element and the second light receiving element.

The present invention also includes an element energizing means for applying a voltage to the semiconductor laser element to energize the current,
Voltage current measuring means for measuring a voltage applied to the semiconductor laser element by the element energizing means and a current to be energized.

Further, the present invention controls the operation of the element energizing means so that the current energized to the semiconductor laser element gradually increases when the output of light emitted from the semiconductor laser element is measured by the first light receiving element,
Control means for controlling the operation of the element energizing means to stop energization of the semiconductor laser element when the light output detected by the first light receiving element reaches a predetermined value.

  According to the present invention, the control means determines the quality of the semiconductor laser element based on the measurement output of the voltage / current measurement means.

The present invention relates to a die bonding method for a semiconductor laser element in which the direction of the optical axis, which is the axis of light emitted from the semiconductor laser element, is adjusted and die bonded to the stem.
Measuring a position of a light emitting point that is a position where light is emitted from the semiconductor laser element;
Moving the semiconductor laser element so that the position of the measured light emitting point is a predetermined origin position;
Adjusting the output of light emitted from the semiconductor laser element to a predetermined output value;
Measuring a peak position at which the output of light emitted from the semiconductor laser element is maximized;
A die bonding method for a semiconductor laser device, comprising: obtaining a deviation amount of the peak position with respect to the origin position and adjusting an optical axis direction of light emitted from the semiconductor laser element based on the deviation amount.

The present invention also includes a step of measuring a voltage applied to the semiconductor laser element and a current supplied to the semiconductor laser element when measuring the output of light emitted from the semiconductor laser element;
And determining whether the semiconductor laser device is good or bad based on the measured voltage and current.

Further, the present invention includes a step of measuring the position of a light emitting point, which is a position where light is emitted from a semiconductor laser element.
The position of the light emitting point is determined by energizing the semiconductor laser element with a current of a threshold value or less to emit light and detecting the center of gravity of the light emitting point image.

In the present invention, the detection of the center of gravity of the light emission point image
It is performed using a camera for imaging a semiconductor laser element.

  According to the present invention, the light emitting point position measuring means for measuring the position of the light emitting point that is the position where the light is emitted from the semiconductor laser element, the first light receiving element for measuring the output of the light emitted from the semiconductor laser element, A second light receiving element that receives the radiated light from the semiconductor laser element through the slit and measures the peak position, and the first light receiving element and the second light receiving element are configured as an integral member. Simple and compact.

  In addition, since the deviation of the optical axis with respect to the light emitting point position can be easily obtained from the measured light emitting point position and the peak position of the emitted light, the semiconductor laser element can be positioned with high accuracy and then die bonded. A die bonding apparatus for a semiconductor laser element that can be realized is realized.

  Further, according to the present invention, the first light receiving element and the second light receiving element which are integrally formed by the light receiving element driving means can be moved in the direction perpendicular to the optical axis. The relative position between the first light receiving element and the second light receiving element can be changed, and the measurement of the light output by the first light receiving element and the measurement of the peak position by the second light receiving element can be easily realized. At the same time, the measurement can be easily switched.

  According to the invention, the first light receiving element is arranged such that the light receiving surface for receiving the light emitted from the semiconductor laser element has an inclination angle with respect to the normal of the optical axis, so that the emitted light is the first light receiving element. It is prevented from being reflected by the light receiving element and entering the light emitting surface of the semiconductor laser element. As a result, the semiconductor laser element is not affected by disturbance light, so that the light output can be accurately measured.

  Further, according to the present invention, since the light receiving element signal adjusting means for variably adjusting the intensity of the signal output from the first light receiving element and the second light receiving element is included, the signal intensity output from the first and second light receiving elements. Regardless of the magnitude, the intensity of the signal input to the control unit can be adjusted to an arbitrary magnitude. This makes it possible to perform positioning measurement of a wide range of semiconductor laser elements from a low output type to a high output type.

  Further, according to the present invention, element energizing means for energizing the semiconductor laser element by applying a voltage, and voltage current measuring means for measuring the voltage applied to the semiconductor laser element by the element energizing means and the energized current. Therefore, the voltage and current measurement results can be used for quality determination of the semiconductor laser device.

  According to the invention, when the control means measures the output of light emitted from the semiconductor laser element with the first light receiving element, the element energizing means is configured so that the current energized to the semiconductor laser element gradually increases. The operation of the element energizing means is controlled so that the energization of the semiconductor laser element is stopped when the light output detected by the first light receiving element reaches a predetermined value. As a result, an unnecessary large load is not applied to the semiconductor laser element, so that damage to the semiconductor laser element during positioning can be prevented.

  Further, according to the present invention, the control means can determine the quality of the semiconductor laser element based on the measurement output of the voltage / current measurement means. Accordingly, the quality of the semiconductor laser element can be determined at the positioning stage, and when the quality of the semiconductor laser element is poor, die bonding can be prevented from being executed. As a result, the occurrence of member loss can be prevented and the working efficiency can be improved.

  According to the die bonding method of the semiconductor laser device of the present invention, it is possible to position the semiconductor laser device with high accuracy and then perform die bonding.

  In addition, according to the present invention, since it includes the step of judging the quality of the semiconductor laser element based on the voltage / current of the semiconductor laser element, it is possible to prevent the outflow of defective products to the steps after the positioning and prevent the occurrence of member loss and work. Improved efficiency is achieved.

  According to the invention, in the step of measuring the position of the light emitting point of the semiconductor laser element, the position of the light emitting point is determined by detecting the center of gravity of the light emitting point image by applying a current below the threshold value to the semiconductor laser element to emit light. Determined. Thus, the position of the light emitting point can be accurately obtained without overloading the semiconductor laser element.

  Further, according to the present invention, since the center of gravity of the light emission point image is detected using the camera that images the semiconductor laser element, the light emission point position can be accurately obtained with a simple configuration.

  FIG. 1 is a system diagram schematically showing a configuration of a semiconductor laser element die bonding apparatus 20 according to an embodiment of the present invention. FIG. 2 is an electrical diagram related to a control operation in the semiconductor laser element die bonding apparatus 20 shown in FIG. It is a block diagram which shows a typical structure.

  A semiconductor laser element die bonding apparatus 20 (hereinafter abbreviated as a die bonding apparatus 20) is roughly composed of a CCD camera 21, which is a light emitting point position measuring means, a first light receiving element 22, a second light receiving element 23, a first and a second light receiving element. The light receiving element driving means 24 for moving the second light receiving elements 22 and 23, the light receiving element signal adjusting means 25 for adjusting the intensity of the signal detected by the first and second light receiving elements 22 and 23, and the semiconductor laser element 26 Positioning stage 27 to be mounted, positioning stage drive unit 28 for driving positioning stage 27, element energizing means 33 for applying a voltage to semiconductor laser element 26 and energizing the current, and voltage applied to semiconductor laser element 26 And the voltage / current measuring means 31 for measuring the energized current and the overall operation of the die-bonding apparatus 20 through the operation control of each of the above parts. Configured to include a control unit 32 is that the control means.

  The die bonding apparatus 20 is used to die bond the semiconductor laser element 26 to a stem (not shown) by adjusting the direction of the optical axis that is the axis of light emitted from the semiconductor laser element 26. In FIG. 1A, a system related to the configuration of the die bonding apparatus 20 is shown in a top view, but the CCD camera 21 and the control system are not shown, and the overall configuration is shown in the side view of FIG. .

  In this embodiment, the positioning stage 27 on which the semiconductor laser element 26 is placed is constituted by an XYθ table. Here, the XYθ table is movable in the two-dimensional direction of the XY axis in the XY plane parallel to the horizontal plane, and is rotated around any position selected in the XY coordinate system. It means a table that can be configured. The positioning stage drive unit 28 is configured by, for example, a stepping motor and a gear train connected to the stepping motor capable of controlling the rotation amount with high accuracy, and is driven according to an operation command from the control unit 32 to move the positioning stage 27. The semiconductor laser element 26 placed on the positioning stage 27 can be moved to a desired position.

  The element energizing means 33 that applies a voltage to the semiconductor laser element 26 and energizes the current includes a probe 29 having a pair of electrical contact terminals, a probe power supply 30, and a probe moving means (not shown). The probe 29 is attached to the probe moving means and is configured to be close to and away from the semiconductor laser element 26 placed on the positioning stage 27, and is formed in the semiconductor laser element 26 by approaching the semiconductor laser element 26. It can be detached from the energizing terminal by coming into contact with the energizing terminal and separating from the semiconductor laser element 26.

  Electric power is supplied to the probe 29 from the probe power supply 30. Therefore, when the probe 29 is in contact with the energization terminal of the semiconductor laser element 26, a voltage can be applied to the semiconductor laser element 26 and a current can flow. The magnitude of the voltage and current applied to the semiconductor laser element 26 can be adjusted by the control unit 32 controlling the operation of the probe power supply 30.

  The semiconductor laser element 26 oscillates with electric power supplied via the probe 29 and emits laser light from the light emitting surface. Here, the radiation shape of the light emitted from the semiconductor laser element 26 is defined as a light emission pattern. The CCD camera 21, which is a light emitting point position measuring means, is disposed above the positioning stage 27, that is, above the semiconductor laser element 26 mounted on the positioning stage 27, and is a semiconductor laser that is energized and emits light. The element 26 is imaged. The position of the light emission point is determined based on the center of gravity of the light emission point image detected from the captured image.

  Here, the center of gravity of the light emission point image means an output level (intensity) of an image signal captured by the CCD camera 21 × an average value of coordinates of an image captured by the CCD camera 21.

  FIG. 3 is a diagram illustrating an example of imaging of the semiconductor laser element 26 by the CCD camera 21. When the semiconductor laser element 26 is imaged by the CCD camera 21, that is, when the light emission pattern 42 is detected, it is preferable that a current equal to or less than a threshold is supplied to the semiconductor laser element 26 to emit light. Here, the threshold means a current value at which laser oscillation starts when the die-bonded semiconductor laser element is put into practical use. By emitting light with a current value equal to or less than the threshold value, it is possible to prevent the semiconductor laser element from being overloaded, so that damage can be prevented.

  The image of the semiconductor laser element 26 taken by the CCD camera 21 does not need to capture the entire shape of the semiconductor laser element 26 in the field of view, and can capture the position of the light emitting point 41 and the light emitting point image in the field of view. It is desirable to select a magnification that is as high as possible. By increasing the magnification of the photographed image, the positioning accuracy of the light emitting point 41 can be increased.

  The position of the light emission point 41 determines the center of gravity of the detected light emission point image as the light emission point 41. Such an operation for obtaining the position of the light emitting point 41 based on the image information of the CCD camera 21 is realized by the control unit 32.

  The position of the light emitting point 41 is recognized by the control unit 32 as a predetermined XY coordinate position on the XY plane that is the plane on which the positioning stage 27 moves. The semiconductor laser element 26 is die-bonded to the stem after being adjusted so that the position and direction of the light emitting point 41 and the optical axis, which will be described later, become a predetermined position and direction. Since the semiconductor laser element 26 is die-bonded to the stem and is used as, for example, a light source of an optical pickup device, the light emitting point 41 and the optical axis of the semiconductor laser element 26 coincide with the optical axis of the optical system of the optical pickup device. In order to do so, positioning is required.

  First, a predetermined position related to the light emitting point 41 will be described. The predetermined position related to the light emitting point 41 is stored in advance in a memory 34 which is a storage unit provided along with the control unit 32 as visual field information regarding the visual field captured by the CCD camera 21.

  In the present embodiment, the imaging field is defined by an XY coordinate system that is the coordinates of the moving plane of the positioning stage 27, and the origin (represented by reference numeral 43) is defined as a predetermined position. When the light emitting point 41 obtained from the light emitting point image center of gravity is at a coordinate position different from the origin 43, the control unit 32 outputs an operation command to the positioning drive unit 28 based on the imaging information by the CCD camera 21, and The positioning stage 27 is moved so that the light emitting point 41 coincides with the origin 43. The movement of the light emitting point 41 to the origin 43 is performed in a state where the probe 29 is detached from the energization terminal of the semiconductor laser element 26.

  The control unit 32 is a processing circuit, and is realized by, for example, a microcomputer including a central processing unit (CPU). The control unit 32 is provided with a memory 34 that is a storage unit. As the memory 34, a known storage device such as a hard disk drive (HDD), a read only memory (ROM), and a random access memory (RAM) can be used. The control unit 32 performs overall operation control of the die bonding apparatus 20 according to an operation control program stored in advance in the memory 34.

  Next, the first and second light receiving elements 22 and 23 will be described. Each of the first and second light receiving elements 22 and 23 is configured by a photoelectric conversion element such as a photodiode (PD). The first light receiving element 22 and the second light receiving element 23 can be opposed to the support arm member 44 whose plan view is substantially L-shaped, and the light receiving surface thereof can face the light emitting surface 26 a of the semiconductor laser element 26. It is put on. In the present embodiment, the first light receiving element 22 is mounted in the vicinity of the end of the protruding member 44 a that protrudes toward the semiconductor laser element 26 of the support arm member 44 that forms the back L-shape, and the light emitting surface of the semiconductor laser element 26 The second light receiving element 23 is mounted in the vicinity of the end of the parallel member 44b extending in parallel with 26a. Thus, since the first and second light receiving elements 22 and 23 are attached to the support arm member 44, the first and second light receiving elements 22 and 23 and the support arm member 44 constitute an integral member.

  The light receiving element drive unit 24 is a drive mechanism including, for example, an electric motor, a pinion attached to the output shaft of the electric motor, and a rack attached to the support arm member 44. The support arm member 44 is connected to the semiconductor laser. The element 26 is moved in the direction of the arrow 45, which is parallel to the light receiving surface 26a of the element 26, so as to freely advance and retract. When the support arm member 44 is moved in the direction of the arrow 45, the first and second light receiving elements 22 and 23 attached to the support arm member 44 are moved in the direction of the arrow 45 and are relative to the semiconductor laser element 26. Can be changed.

  The first light receiving element 22 is used to receive light emitted from the semiconductor laser element 26 and measure the light output when the first light receiving element 22 is at a position facing the light emitting surface 26 a of the semiconductor laser element 26. Therefore, the first light receiving element 22 may be referred to as a power measuring light receiving element.

  FIG. 4 is a diagram for explaining a method of measuring light output by the first light receiving element 22. When the first light receiving element 22 is attached to the support arm member 44, the light receiving surface 22 a that receives the light 46 emitted from the semiconductor laser element 26 has an inclination angle α with respect to the perpendicular 48 of the optical axis 47. Placed in. As a result, the radiation light 46 is prevented from being reflected by the light receiving surface 22a of the first light receiving element 22 and entering the light emitting surface 26a of the semiconductor laser element 26, and the semiconductor laser element 26 is affected by disturbance light. Therefore, it is possible to accurately measure the light output. The light output is measured in a state where the light emission point 41 is moved so as to coincide with the origin 43 and then the probe 29 is again brought into contact with the energization terminal of the semiconductor laser element 26 to emit light.

  When the output of the light 46 emitted from the semiconductor laser element 26 is measured by the first light receiving element 22, the control unit 32 controls the operation of the probe power supply 30, so that the current supplied to the semiconductor-the-element 26 is changed. Increase gradually. Further, the control unit 32 increases the energization current to the semiconductor laser element 26 so that when the light output detected by the first light receiving element 22 reaches a predetermined value, the probe power supply is stopped so that the energization to the semiconductor laser element 26 is stopped. 30 operations can be controlled.

  In the die bonding apparatus 20, the voltage between the probes 29 (applied voltage) and the current flowing between the probes 29, in other words, the semiconductor laser, are measured in parallel with the measurement of the light output of the radiated light 46 by the first light receiving element 22. The voltage value applied to the element 26 and the energized current value are measured by a voltage / current monitor circuit which is the voltage / current measuring means 31. The measurement result by the voltage / current monitor circuit 31 is input to the control unit 32, and the control unit 32 determines the quality of the semiconductor laser element 26 based on the output of the voltage / current monitor circuit 31.

  Further, in the die bonding apparatus 20 of the present invention, the quality of the semiconductor laser element 26 is determined by the light output value detected by the first light receiving element 22 together with the measurement output of the voltage / current monitor circuit 31.

  The quality determination of the semiconductor laser element 26 based on the light output value is performed as follows. When the light output value detected and received by the first light receiving element 22 and input to the control unit 32 does not reach the specified output value that is predetermined for each model of the semiconductor laser element 26 and stored in the memory 34, The control unit 32 controls the probe power supply 30 to increase the voltage applied to the semiconductor laser element 26 and repeats the operation of comparing whether or not the obtained optical output value reaches the specified output value. Even if the voltage applied to the semiconductor laser element 26 is increased to the maximum applied voltage that is predetermined for each model of the semiconductor laser element 26 and stored in the memory 34, the optical output of the semiconductor laser element 26 rises to the specified value. If not, it is determined that the light emission is defective, that is, the quality is poor.

  Further, when the applied voltage is large and the light output is small, a light emission failure of the semiconductor laser element 26 is considered. In addition, if the applied current is large and the optical output is near 0 even though the applied voltage is small, it is conceivable that the probes 29 are short-circuited. Furthermore, data such as the oscillation threshold current value and the oscillation differential efficiency, which are important characteristics of the semiconductor laser element 26, can be obtained from the relationship of the energization current with respect to the applied voltage.

  As described above, the quality determination of the semiconductor laser element 26 and the failure determination of the apparatus can be performed in parallel with the positioning, so that it is possible to prevent a defective product from flowing into the processes after the die bonding and the positioning with the apparatus in an abnormal state. Thus, die bonding can be prevented. As a result, it is possible to improve the operating rate by feeding back the malfunction of the device at an early stage, and to reduce the loss of components consumed in the post-process by preventing the outflow of defective products to the post-process, and to improve the work efficiency. It becomes possible.

  Measurement conditions such as an application start voltage, an increase step value of the applied voltage, a specified value of optical output, a maximum applied voltage, and the like used for optical output measurement of the semiconductor laser element depend on the type of the semiconductor laser element. Accordingly, the conditions used for measuring the optical output for each model of the semiconductor laser element are stored in advance in the memory 34 as table data. If the model of the semiconductor laser element to be die-bonded is determined, the table data corresponding to the model is stored in the memory. It is possible to easily change the measurement conditions by reading from 34 and making it available.

  On the second light receiving element 23, a slit member 50 having a slit 49 extending in a direction orthogonal to the moving direction of the support arm member 44 indicated by an arrow 45 is mounted on the light receiving surface 23a. Therefore, the second light receiving element 23 receives the light subdivided by the slit 49 by being emitted from the semiconductor laser element 26 and passing through the slit 49.

  The second light receiving element 23 receives the light subdivided by the slit 49 while moving in the direction of the arrow 45, thereby measuring the peak position where the output of the light 46 emitted from the semiconductor laser element 26 is maximized. At the same time, since the radiation angle that is the spread angle of the radiation light 46 can be measured, the second light receiving element 23 may be referred to as a radiation angle measuring light receiving element.

  Hereinafter, measurement of the peak position and the radiation angle by the second light receiving element 23 will be described. 5 and 6 are diagrams illustrating a method for measuring the peak position and the radiation angle by the second light receiving element 23. FIG. FIG. 5 shows a radiation state adjusted so that a current is applied by applying a voltage to the semiconductor laser 26 and an optical output becomes a specified output value.

  In FIG. 5A, the first and second light receiving elements 22, 23 and the support arm member 44 that are integrally configured have a light 46 a that forms one side that forms a radiation angle of the light emission pattern of the radiation light 46. Is in a position where it can enter the second light receiving element 23 through the slit 49. This position is called a radiation angle measurement start position for convenience.

  In FIG. 5B, the first and second light receiving elements 22 and 23 and the supporting arm member 44 which are integrally formed are configured such that the first light receiving element 22 is the semiconductor laser element in the direction of the arrow 45 shown above. The state which moved to the arrow 51 direction which is a direction away from 26 is shown. That is, the first and second light receiving elements 22, 23 and the support arm member 44 that are integrally formed, the light 46 b that forms the other side forming the emission angle of the emission pattern of the emitted light 46 passes through the slit 49. Thus, the light can enter the second light receiving element 23. This position is called a radiation angle measurement end position for convenience.

  In FIG. 6, the movement trajectory of the second light receiving element 23 will be described. Since the second light receiving element 23 measures the radiation angle, the movement movement locus from the radiation angle measurement start position to the radiation angle measurement end position is the light emission point 41 of the semiconductor laser element 26 as shown in FIG. It is preferable that the arc 52 is centered on the arc. However, when the second light receiving element 23 is moved in the shape of the arc 52, the apparatus configuration for moving the movement becomes complicated, and the exclusive occupation area 53 required for the movement to avoid interference with other mechanical units becomes large. Therefore, the size of the apparatus is increased. On the other hand, since the exclusive occupation area 54 can be reduced by linearly moving the second light receiving element 23 as in the embodiment of the present invention shown in FIG. 6B, the apparatus can be downsized. It is advantageous.

  While the second light receiving element 23 is linearly moved parallel to the light emitting surface 26 a of the semiconductor laser element 26, the subdivided light is received by the second light receiving element 23 through the slit 49. At this time, the light output intensity distribution of the light emission pattern can be obtained from the relationship between the position information of the second light receiving element 23 and the light output intensity. The position information of the second light receiving element 23 can be obtained by detecting the position or moving distance of the support arm member 44 by the light receiving element driving unit 24 with a position sensor, for example, and inputting it to the control unit 32.

A line 55 in FIG. 5C shows the light output intensity distribution. The linear movement distance w from the radiation angle measurement start position to the radiation angle measurement end position of the second light receiving element 23 and both when the light receiving surface 23a of the second light receiving element 23 faces the light emitting surface 26a of the semiconductor laser element 26 From the distance L, the radiation angle θr is given by equation (1). The calculation for obtaining the radiation angle θr is performed by the control unit 32.
θr = tan ⁻¹ (w / L) (1)

Next, the emission axis deviation amount θ is obtained. FIG. 7 is a diagram illustrating an outline of a method for obtaining the issue axis deviation amount θ. Here, the emission axis deviation amount θ is defined as follows. The second light receiving element 23 moves between the peak position 56 where the light output intensity obtained from the light output intensity distribution 55 is maximum and the virtual light emitting axis 57 passing through the light emitting point 41 of the semiconductor laser element 26 and perpendicular to the light emitting surface 26a. When the separation distance in the direction is d, the angle is given by Expression (2) by the above-described distance L, that is, the distance L on the virtual light emitting axis 57 from the light emitting surface 26a to the light receiving surface 23a. The control unit 32 also calculates the light emission axis deviation amount θ.
θ = tan ⁻¹ (d / L) (2)

  When the calculation of the expressions (1) and (2) by the control unit 32 is completed, that is, when the measurement of the radiation angle θr, the peak position 56, and the emission axis deviation amount θ is completed, the control unit 32 applies the voltage to the semiconductor laser element 26 Is stopped, and the probe 29 is detached from the energization terminal of the semiconductor laser element 26.

  Next, the control unit 32 outputs an operation command to the positioning stage driving unit 28 and moves the positioning stage 27 to correct the light emission axis deviation amount θ. At this time, the control unit 32 determines the rotation center coordinate in the XY coordinate system in advance as the light emitting point 41, calculates the coordinate after the rotational movement around the coordinate position of the light emitting point 41, and determines the movement amount. By taking the XY-θ correction into consideration, the emission axis deviation amount θ can be corrected without shifting the position of the light emitting point 41 on the XY coordinates.

  The light output from the first and second light receiving elements 22 and 23 varies greatly depending on the model of the semiconductor laser element 26. Therefore, if the optical output signals from the first and second light receiving elements 22 and 23 are directly input to the control unit 32, the operation allowable signal intensity of the control unit 32 may be exceeded if the semiconductor laser element 26 is a high output model. On the contrary, when the semiconductor laser element 26 is a low-output model, the output is low, so that the S / N ratio may be deteriorated and the semiconductor laser element 26 may not operate normally.

  In the die bonding apparatus 20 of the present embodiment, the light receiving element signal adjusting means 25 is provided between the first and second light receiving elements 22 and 23 and the control unit 32 in order to solve such a problem.

  The light receiving element signal adjusting means 25 is, for example, a circuit that amplifies an electric signal that is received by the light receiving elements 22 and 23 and converted into an optical signal. When the semiconductor laser element 26 is a low output model, the light receiving element signal adjustment means 25 increases the signal intensity with a large amplification gain and inputs it to the control unit 32. When the semiconductor laser element 26 is a high output model, the light receiving element signal adjustment means 25 Conversely, the signal intensity is weakened and input to the control unit 32. Thus, in the die bonding apparatus 20, the intensity of the output signal from the first and second light receiving elements 22 and 23 is always in an appropriate state for the operation of the control unit 32 regardless of the output type of the semiconductor laser element. It becomes possible to input.

  As for the amplification gain by the light receiving element signal adjustment means 25, an appropriate gain is stored as table data in advance in the memory 34 for each model of the semiconductor laser element, and it corresponds to that model according to the model of the semiconductor laser element to be die-bonded. By making the table data to be read out from the memory 34 and making it available, the gain can be easily changed appropriately.

  FIG. 8 is a flowchart for explaining a die bonding method for a semiconductor laser device according to one embodiment of the present invention. Hereinafter, a die bonding method of the semiconductor laser element will be described with reference to FIG. Note that the operations of the flowchart are executed by each unit of the die bonding apparatus 20 in accordance with an operation command output from the control unit 32 unless otherwise specified.

  At the start of the flowchart, the operation power supply of the die bonding apparatus 20 is turned on by the operator and can be operated, and the transport apparatus capable of mounting and removing the semiconductor laser element on the positioning stage 27 is also operable. It is in.

  In step s1, the semiconductor laser element 26 is placed on the positioning stage 27 by the transport device. In step s2, the probe 29 of the element energization means 33 is moved and brought into contact with the energization terminal of the semiconductor laser element 26. Next, a voltage is applied to the semiconductor laser element 26 from the probe power supply 30 of the element energizing means 33 via the probe 29, and a current is applied to cause the semiconductor laser element 26 to emit light. At this time, the probe power supply 30 is controlled to emit light so that the current flowing through the semiconductor laser element 26 is less than or equal to the threshold current.

  In step s3, the position of the light emitting point 41 is measured from the light emitting point image barycentric position based on the image data taken by the CCD camera 21. In step s4, power supply to the semiconductor laser element 26 is stopped, and light emission is stopped. In step s 5, based on the measured position information of the light emission point 41, the operation of the positioning stage drive unit 28 is controlled to move the positioning stage 27, and the light emission point 41 is corrected to the origin position 43.

  In step s 6, power is again supplied from the probe power supply 30 to the semiconductor laser element 26 via the probe 29 to emit light. At this time, the operation of the probe power supply 30 is controlled, and the semiconductor laser element 26 is energized with a current value that radiates with an optical output smaller than the specified output value. In step s 7, the light receiving element driving unit 24 is operated to move the first light receiving element 22 to a position facing the semiconductor laser element 26, and the optical output of the semiconductor laser element 26 is received by the light reception signal of the first light receiving element 22. Measure. In step s8, the voltage applied to the semiconductor laser element 26 and the flowing current are measured through the voltage / current monitor circuit 31.

  In step s9, the measured light output is compared with the specified output read from the memory 34 to determine whether or not the specified output has been reached. Here, the prescribed output is an output that is practically required for use of the semiconductor laser element 26 when mounted on a practical device, and is predetermined in design and stored in the memory 34. When the light output does not reach the specified output, the process proceeds to step s10. In step s10, the probe power supply 30 is controlled to increase the voltage applied to the semiconductor laser element 26 and the current to be applied. At this time, the probe power supply 30 is controlled to have a small increase width so as to gradually increase the energization current instead of increasing the current at a stretch with a large width. After increasing the voltage / current, the process returns to step s7 and proceeds to the subsequent steps.

  In step s11, in addition to the measured optical output, the voltage value and the current value measured through the voltage / current monitor circuit 31 are compared with a voltage / current value predetermined as a quality reference value read from the memory 34, and the semiconductor laser device 26 It is determined whether or not it is a non-defective product.

  When the semiconductor laser element 26 is a defective product, the process proceeds to step s17, the power supply to the semiconductor laser element 26 is stopped, and light emission is stopped. In step s18, the transport device is operated to remove the semiconductor laser element 26 from the positioning stage 27, and the process returns to step s1. That is, a new semiconductor laser element is extracted and placed on the positioning stage 27 by the transfer device, and the subsequent steps are executed.

  On the other hand, when the semiconductor laser element 26 is a good product, the process proceeds to step s12. In step s12, the power supplied from the probe power supply 30 is adjusted so that the optical output of the semiconductor laser element 26 is stabilized at the specified output value. In step s12, the light emission may be temporarily stopped when the light output reaches the specified output value, and the light emission may be started again and adjusted so as to reach the specified output value. In step s13, the operation of the light receiving element driving unit 24 is controlled to move the second light receiving element 23 to the radiation angle measurement start position, and then scanned to the radiation angle measurement end position at a constant speed. The position and emission axis deviation amount θ are measured. In step s14, power supply to the semiconductor laser element 26 is stopped, and light emission is stopped.

  In step s15, the operation of the positioning stage drive unit 28 is controlled to move the positioning stage 27, and the light emission axis deviation is corrected. Thereafter, the process proceeds to step s16, the light emitting point position and the light emitting axis deviation are corrected, and the positioned semiconductor laser element 26 is picked up by a pickup collet and die-bonded. Next, when there is no semiconductor laser element for further positioning and die bonding, the process proceeds to the end, and the die bonding operation is completed.

  When there is a semiconductor laser element to be newly positioned, the process returns to step s1, a new semiconductor laser element is placed on the positioning stage 27 by the transport device, and the subsequent steps are executed.

1 is a system diagram schematically showing a configuration of a die bonding apparatus 20 for a semiconductor laser device according to an embodiment of the present invention. It is a block diagram which shows the electrical structure which concerns on the control action in the die-bonding apparatus 20 of the semiconductor laser element shown in FIG. 2 is a diagram illustrating an example of imaging of a semiconductor laser element 26 by a CCD camera 21. FIG. FIG. 5 is a diagram for explaining a method for measuring light output by a first light receiving element 22; It is a figure explaining the measuring method of the peak position and radiation angle by the 2nd light receiving element. It is a figure explaining the measuring method of the peak position and radiation angle by the 2nd light receiving element. It is a figure explaining the outline | summary of the method of calculating | requiring the issue axis deviation | shift amount (theta). It is a flowchart explaining the die-bonding method of the semiconductor laser element which is 1 aspect of this invention. It is a figure which shows the light emission state of a semiconductor laser element. FIG. 3 is a diagram showing a difference in light emission pattern due to a difference in light emission output of the semiconductor laser element 1. It is a figure which shows the far-field image and luminance distribution of the semiconductor laser element 1 input into a light receiving element. It is a timing chart which shows the timing of pulse light emission, and the timing of shutter opening.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Die bonding apparatus 21 CCD camera 22 1st light receiving element 23 2nd light receiving element 24 Light receiving element drive means 25 Light receiving element signal adjustment means 26 Semiconductor laser element 27 Positioning stage 28 Positioning stage drive part 29 Probe 30 Probe power supply 31 Voltage current monitor circuit 32 Control unit 33 Element energizing means

Claims (11)

In a die-bonding apparatus for a semiconductor laser element that adjusts the direction of the optical axis that is the axis of light emitted from the semiconductor laser element and die-bonds the semiconductor laser element to the stem,
A light emitting point position measuring means for measuring a position of a light emitting point which is a position where light is emitted from the semiconductor laser element;
A first light receiving element that receives light emitted from the semiconductor laser element and measures a light output;
A second light receiving element that receives light emitted from the semiconductor laser element through a slit and measures a peak position at which the light output is maximized;
A die bonding apparatus for a semiconductor laser element, wherein the first light receiving element and the second light receiving element constitute an integral member.   2. A die bond for a semiconductor laser device according to claim 1, further comprising: a light receiving element driving means for moving the first light receiving element and the second light receiving element which are integrally formed in a direction perpendicular to the optical axis. apparatus. The first light receiving element is
3. The die bonding apparatus for a semiconductor laser device according to claim 1, wherein the light receiving surface for receiving the light emitted from the semiconductor laser device is disposed so as to have an inclination angle with respect to the normal of the optical axis.   4. The semiconductor laser device according to claim 1, further comprising: a light receiving element signal adjusting unit that variably adjusts the intensity of a signal output from the first light receiving element and the second light receiving element. Die bond equipment. An element energization means for energizing the semiconductor laser element by applying a voltage;
5. A voltage / current measuring means for measuring a voltage applied to the semiconductor laser element by the element energizing means and a current to be energized, and a semiconductor laser element according to claim 1, Die bond equipment. When measuring the output of light emitted from the semiconductor laser element with the first light receiving element, the operation of the element energizing means is controlled so that the current energized to the semiconductor laser element gradually increases,
6. A control means for controlling the operation of the element energization means to stop energization of the semiconductor laser element when the light output detected by the first light receiving element reaches a predetermined value. Die bonding apparatus for semiconductor laser devices. The control means
7. The die bonding apparatus for a semiconductor laser device according to claim 6, wherein the quality of the semiconductor laser device is determined based on a measurement output of the voltage / current measuring means. In a die-bonding method of a semiconductor laser element, in which the direction of the optical axis that is the axis of light emitted from the semiconductor laser element is adjusted and the semiconductor laser element is die-bonded to the stem,
Measuring a position of a light emitting point that is a position where light is emitted from the semiconductor laser element;
Moving the semiconductor laser element so that the position of the measured light emitting point is a predetermined origin position;
Adjusting the output of light emitted from the semiconductor laser element to a predetermined output value;
Measuring a peak position at which the output of light emitted from the semiconductor laser element is maximized;
A die bonding method for a semiconductor laser element, comprising: obtaining a deviation amount of the peak position with respect to the origin position and adjusting an optical axis direction of light emitted from the semiconductor laser element based on the deviation amount. A step of measuring a voltage applied to the semiconductor laser element and a current supplied to the semiconductor laser element when measuring the output of light emitted from the semiconductor laser element;
9. The die bonding method for a semiconductor laser device according to claim 8, further comprising a step of determining the quality of the semiconductor laser device based on the measured voltage and current. In the step of measuring the position of the emission point, which is the position where light is emitted from the semiconductor laser element,
10. The die bonding method for a semiconductor laser device according to claim 9, wherein the position of the light emitting point is determined by applying a current below a threshold value to the semiconductor laser device to emit light and detecting the center of gravity of the light emitting point image. The detection of the center of gravity of the luminous point image
11. The die bonding method for a semiconductor laser device according to claim 10, wherein the die bonding method is performed using a camera for imaging the semiconductor laser device.

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