WO2022264972A1 - Chip-on-submount - Google Patents

Chip-on-submount Download PDF

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Publication number
WO2022264972A1
WO2022264972A1 PCT/JP2022/023669 JP2022023669W WO2022264972A1 WO 2022264972 A1 WO2022264972 A1 WO 2022264972A1 JP 2022023669 W JP2022023669 W JP 2022023669W WO 2022264972 A1 WO2022264972 A1 WO 2022264972A1
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WO
WIPO (PCT)
Prior art keywords
submount
laser element
chip
coating layer
center
Prior art date
Application number
PCT/JP2022/023669
Other languages
French (fr)
Japanese (ja)
Inventor
泰雅 川北
雅和 三浦
宏辰 石井
哲也 竹内
Original Assignee
古河電気工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 古河電気工業株式会社 filed Critical 古河電気工業株式会社
Priority to JP2023529864A priority Critical patent/JPWO2022264972A1/ja
Priority to CN202280040982.XA priority patent/CN117461225A/en
Publication of WO2022264972A1 publication Critical patent/WO2022264972A1/en
Priority to US18/534,857 priority patent/US20240106189A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/023—Mount members, e.g. sub-mount members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/0233—Mounting configuration of laser chips
    • H01S5/02345—Wire-bonding

Definitions

  • the present invention relates to a chip-on-submount.
  • the inventors found that, for example, depending on the mounting position of the laser element with respect to the submount, the mounting position of the bonding wire with respect to the laser element, etc., the laser light output from the laser element is polarized. It was found that rotation (misalignment) occurs, making it difficult to obtain the desired optical characteristics in some cases.
  • one of the objects of the present invention is to obtain a novel and improved chip-on-submount that can, for example, suppress polarization rotation caused by mounting components.
  • a chip-on-submount of the present invention includes, for example, a submount having a first surface facing a first direction, and a submount mounted on the first surface, extending across the first direction, and extending in the first direction.
  • a covering layer having a second surface facing toward; a third surface mounted on said second surface and facing said first direction; a laser element that extends in a third direction that intersects the first direction and the second direction and that outputs laser light in the third direction; a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, and a residual stress that compresses the coating layer toward the center in the second direction in the coating layer.
  • the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction.
  • a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction.
  • a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; and a bonding wire that applies a pressing force including a force component directed in a direction opposite to the first direction to the laser element, and the coating layer is compressed toward the center of the coating layer in the second direction.
  • a first moment about the central axis of the light emitting part along the third direction caused by an external force acting on the laser element from the coating layer due to the residual stress, and a first moment from the bonding wire to the laser element and a second moment about the central axis of the light-emitting portion generated by the pressing force acting on the light-emitting portion is approximately zero.
  • the light-emitting section is positioned closer to the end of the laser element in the direction opposite to the first direction than the center thereof in the first direction, and the laser element includes the light-emitting section and the second mount. You may have the protrusion part which was located in a line with one direction and protruded in the opposite direction of said 1st direction.
  • the width of the coating layer in the second direction may be narrower than the width of the submount in the second direction and wider than the width of the laser element in the second direction.
  • the thickness of the laser element in the first direction may be 1/3 or less of the thickness of the submount in the first direction.
  • the submount may be made of aluminum nitride, and the coating layer may be made of a copper-based material.
  • the light-emitting portion is shifted in a fourth direction, which is one of the second direction and a direction opposite to the second direction, with respect to the center of the coating layer in the second direction.
  • a pressing position of the bonding wire on the third surface may be shifted in a direction opposite to the fourth direction with respect to the light emitting portion.
  • the center of the laser element in the second direction may be shifted to the side opposite to the pressing position with respect to the center of the coating layer in the second direction.
  • the light-emitting portion may be located on the side opposite to the pressing position with respect to the center of the laser element in the second direction.
  • the pressing position of the bonding wire with respect to the third surface, the position of the light-emitting portion, and the center of the covering layer in the second direction may be aligned in the first direction.
  • a plurality of bonding wires are attached to the third surface as the bonding wires, and a position of a center of gravity in the second direction of pressing positions of the plurality of bonding wires against the third surface; A position of the light emitting portion and a center of the coating layer in the second direction may be aligned in the first direction.
  • the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction.
  • a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction.
  • a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; , and a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, and the light-emitting portion is positioned with respect to the center of the coating layer in the second direction, the is shifted in a fourth direction which is one of the second direction and the direction opposite to the second direction, and the pressing position of the bonding wire against the third surface is in the fourth direction with respect to the light emitting portion located in the opposite direction.
  • the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction.
  • a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction.
  • a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; and a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, wherein the position of the center of gravity in the second direction of the pressing position of the bonding wire on the third surface. and the light emitting portion and the center of the coating layer in the second direction are aligned in the first direction.
  • FIG. 1 is an exemplary and schematic front view of the chip-on-submount of the first embodiment.
  • FIG. 2 is an exemplary and schematic front view of the chip-on-submount of the second embodiment.
  • FIG. 3 is an exemplary and schematic front view of the chip-on-submount of the third embodiment.
  • FIG. 4 is an exemplary and schematic front view of the chip-on-submount of the fourth embodiment.
  • FIG. 5 is an exemplary and schematic front view of the chip-on-submount of the fifth embodiment.
  • a plurality of exemplary embodiments of the present invention are disclosed below.
  • the configurations of the embodiments shown below and the actions and results (effects) brought about by the configurations are examples.
  • the present invention can be realized by configurations other than those disclosed in the following embodiments.
  • at least one of various effects (including derivative effects) obtained by the configuration can be obtained.
  • the X direction is indicated by an arrow X
  • the Y direction is indicated by an arrow Y
  • the Z direction is indicated by an arrow Z.
  • the X-, Y-, and Z-directions intersect and are orthogonal to each other.
  • the X direction is the direction in which laser light is emitted from the laser element and the longitudinal direction of the laser element.
  • the Y direction is the width direction of the laser element.
  • the Z direction is the stacking direction of the submount, the coating layer, and the laser element, and is also called the thickness direction.
  • each drawing is schematic, and the dimensions in the drawing may differ from the actual dimensions.
  • FIG. 1 is a front view of the chip-on-submount 100A (100) of the first embodiment when viewed in the opposite direction to the X direction.
  • the chip-on-submount 100A includes a submount 10, a coating layer 20, a semiconductor laser chip 30, and bonding wires 50.
  • the semiconductor laser chip 30 is an example of a laser element.
  • the submount 10 has a substantially constant thickness in the Z direction and spreads across and perpendicular to the Z direction.
  • the submount 10 has a surface 10a and a surface 10b opposite to the surface 10a.
  • the surface 10a faces in the direction opposite to the Z direction and intersects and is orthogonal to the Z direction.
  • the surface 10b faces the Z direction, intersects the Z direction, and is perpendicular to the Z direction.
  • the side 10a is also called the back side and the side 10b is also called the front side.
  • the surface 10b is an example of a first surface.
  • the Z direction is an example of a first direction.
  • the thickness of the submount 10 is, for example, approximately 0.3 to 1.0 [mm].
  • Materials for the submount 10 include, for example, aluminum nitride (AlN), alumina (Al 2 O 3 ), beryllia (BeO), boron nitride (BN), diamond, silicon nitride (Si 3 N 4 ), and silicon carbide. (SiC), silicon dioxide (SiO 2 ), and zirconia (ZrO 2 ).
  • the thermal expansion coefficients of aluminum nitride, silicon nitride, and silicon carbide are 4.5 ⁇ 10 ⁇ 6 [1/K], 2.8 ⁇ 10 ⁇ 6 [1/K], and 3.7 ⁇ 10 ⁇ 6 [1/K], respectively. /K].
  • a coating layer 20 is attached on the surface 10b of the submount 10.
  • the coating layer 20 has a substantially constant thickness in the Z direction and extends perpendicularly to and crossing the Z direction.
  • the coating layer 20 has a surface 20a and a surface 20b opposite to the surface 20a.
  • the surface 20a faces in the direction opposite to the Z direction and intersects and is orthogonal to the Z direction.
  • the surface 20b faces the Z direction and intersects and is perpendicular to the Z direction.
  • the side 20a is also called the back side and the side 20b is also called the front side.
  • the surface 20b is an example of a second surface.
  • the thickness of the coating layer 20 is, for example, approximately 20 to 200 [ ⁇ m].
  • the covering layer 20 is made of, for example, a copper-based material. Also, the thermal expansion coefficient of copper is 17 ⁇ 10 ⁇ 6 [1/K]. The thermal expansion coefficient of the coating layer 20 is greater than that of the submount 10 .
  • the covering layer 20 may also be called an intermediate layer, a covering member, or an intermediate member.
  • a coating layer (not shown) different from the coating layer 20 is also provided on the surface 10 b of the submount 10 .
  • Both the covering layer 20 and the other covering layer are conductors made of the materials described above.
  • the covering layer 20 and the other covering layer are separated by a groove (gap) and electrically insulated.
  • the coating layer 20 and the other coating layer have multilayer films made of the copper-based materials described above. Note that the submount 10 in this embodiment is sometimes referred to as a substrate, and the substrate including the coating layer (the submount 10 in this embodiment) is sometimes referred to as a submount.
  • a semiconductor laser chip 30 is mounted on the surface 20b of the coating layer 20 via a bonding material 40 having conductivity.
  • the bonding material 40 is, for example, AuSn solder.
  • the bonding material 40 is heated to a temperature higher than its melting point in the reflow process and solidified by being cooled down to about room temperature to bond the coating layer 20 and the semiconductor laser chip 30 together.
  • the semiconductor laser chip 30 has a substantially constant thickness in the Z direction and spreads across and perpendicular to the Z direction.
  • the semiconductor laser chip 30 has a surface 30a and a surface 30b opposite to the surface 30a.
  • the surface 30a faces in the direction opposite to the Z direction and intersects and is perpendicular to the Z direction.
  • the surface 30b faces the Z direction and intersects and is perpendicular to the Z direction.
  • the semiconductor laser chip 30 has a light emitting portion 31 that outputs laser light in the X direction.
  • the light-emitting portion 31 is positioned in the middle portion of the semiconductor laser chip 30 in the Y direction, that is, in the present embodiment, at the center Cc in the Y direction, and extends in the X direction.
  • the light emitting portion 31 is positioned closer to the surface 30a than the center of the semiconductor laser chip 30 in the Z direction, specifically, in the vicinity of the surface 30a.
  • the surface 30a is also referred to as the front surface and the surface 30b is also referred to as the back surface.
  • the surface 30b is an example of a third surface.
  • the light emitting section 31 is also called an active layer.
  • the semiconductor laser chip 30 is junction-down mounted.
  • the intermediate portion of the semiconductor laser chip 30 in the Y direction means a portion of the semiconductor laser chip 30 between the end in the Y direction and the end in the opposite Y direction.
  • the Y direction is an example of the second direction
  • the X direction is an example of the third direction.
  • the coating layer 20 is electrically connected via a bonding material 40 to an electrode (for example, a p-type electrode, not shown) provided on the surface 30a of the semiconductor laser chip 30 .
  • an electrode for example, a p-type electrode, not shown
  • Another layer on the surface 10b described above is electrically connected to an electrode (for example, an n-type electrode, not shown) provided on the surface 30b of the semiconductor laser chip 30 via a bonding wire 50.
  • the bonding wires 50 are joined and electrically connected to electrodes provided on the surface 30b via a joining material such as AuSn solder.
  • the semiconductor laser chip 30 outputs a laser beam having a wavelength according to its configuration and material.
  • the thickness of the semiconductor laser chip 30 is, for example, about 0.1 [mm].
  • the main component of the semiconductor laser chip 30 is, for example, gallium arsenide (GaAs) or indium phosphide (InP).
  • the thermal expansion coefficients of gallium arsenide and indium phosphide are 5.9 ⁇ 10 ⁇ 6 [1/K] and 4.5 ⁇ 10 ⁇ 6 [1/K].
  • the coefficient of thermal expansion of the coating layer 20 is greater than that of the submount 10, so that when the bonding material 40 is cooled in the reflow process, it shrinks more than the submount 10. . Therefore, in the view of FIG. 1, that is, the front view when the chip-on-submount 100 is viewed in the direction opposite to the X direction, the coating layer 20 has a residual stress Sc that is compressed toward the center Cm in the Y direction. occurs.
  • This residual stress Sc acts as an external force on the surface 30 a of the semiconductor laser chip 30 via the surface 20 b and the bonding material 40 . Due to this external force, a moment M1 about the central axis Ax of the light emitting portion 31 extending in the X direction may act on the light emitting portion 31 .
  • the position Pl of the light-emitting portion 31 is shifted in the opposite direction in the Y direction from the center Cm of the coating layer 20 in the Y direction.
  • a residual stress compressing the center Cm in the Y direction is generated.
  • a portion near the light emitting portion 31 and behind the light emitting portion 31 in the Z direction (downward in FIG. 1) has a Y direction (rightward in FIG. 1).
  • An external force acts toward
  • a counterclockwise moment M1 in FIG. 1 acts on the light emitting portion 31 due to the external force.
  • Moment M1 is an example of a first moment.
  • the direction opposite to the Y direction is an example of the fourth direction. Residual stress that compresses the coating layer 20 in the opposite direction in the Y direction toward the center Cm is generated in a portion in front of the center Cm in the Y direction (to the right in FIG. 1).
  • a pressing force Fw acts from the bonding wire 50 to press the semiconductor laser chip 30 toward the covering layer 20 and the submount 10.
  • the pressing force Fw includes a force component in the direction opposite to the Z direction (downward in FIG. 1).
  • a moment M2 about the central axis Ax of the light emitting portion 31 may act on the light emitting portion 31 due to this pressing force Fw.
  • the pressing position of the bonding wire 50 against the surface 30b of the semiconductor laser chip 30, that is, the connection position Pw of the bonding wire 50 with the surface 30b is the position Pl ( In this embodiment, it is shifted in the Y direction (to the right in FIG. 1) by a shift dw from the center Cc of the semiconductor laser chip 30 in the Y direction).
  • a clockwise moment M2 in FIG. 1 acts on the light emitting portion 31 due to the pressing force Fw.
  • Moment M2 is an example of a second moment.
  • the Y direction is an example of a direction opposite to the fourth direction.
  • the inventors found that the polarization angle of the laser light output from the semiconductor laser chip 30 changes according to the connection position Pw of the bonding wire 50 in the Y direction. Specifically, the inventors manufactured a large number of semiconductor laser chips 30 having different connection positions Pw in the Y direction, and determined that the deviation dw in the Y direction of the connection position Pw from the center Cc of the semiconductor laser chip 30 and the semiconductor laser chip 30 and the polarization rotation angle (rotation deviation from the initial state) in the output laser light. Note that the deviation dw is a manufacturing target value and includes a tolerance range.
  • the sign of the deviation dw was positive (+) when the connection position Pw was deviated in the Y direction from the center Cc, and negative (-) when deviated in the opposite direction of the Y direction.
  • the center Cc of the semiconductor laser chip 30 in the Y direction is the position Pl of the light emitting section 31 (central axis Ax) in the Y direction.
  • the experimental results were as shown below.
  • the position Pl of the light emitting portion 31 is shifted in the direction opposite to the Y direction (fourth direction) with respect to the center Cm of the coating layer 20 in the Y direction, and bonding
  • the connection position Pw of the wire 50 in the Y direction (opposite direction to the fourth direction) with respect to the position Pl of the light emitting section 31, it was possible to suppress the polarization rotation with respect to the desired characteristics. .
  • the light-emitting portion 31 (central axis Ax) is positioned at the center Cc of the semiconductor laser chip 30 in the Y direction.
  • the effect of reducing the polarization rotation angle by such a configuration is that the width Wm of the coating layer 20 in the Y direction is narrower than the width Ws of the submount 10 in the Y direction, and the semiconductor laser chip 30
  • the difference between the width Wm and the width Ws (Ws-Wm) is preferably 1/2 or less of the width Ws, and 1/3 or less of the width Ws was found to be more favorable.
  • the thickness Tc of the semiconductor laser chip 30 in the Z direction is preferably 1 ⁇ 3 or less of the thickness Ts of the submount 10 in the Z direction.
  • FIG. 2 is a front view of the chip-on-submount 100B (100) of the second embodiment when viewed in the opposite direction to the X direction.
  • a chip-on-submount 100B of this embodiment has the same configuration as that of the first embodiment.
  • the position Pl of the light emitting section 31 in the Y direction within the semiconductor laser chip 30B is different from that in the first embodiment. That is, in the present embodiment, in the semiconductor laser chip 30B, the light emitting portion 31 (central axis Ax) is shifted from the center Cc of the semiconductor laser chip 30 in the Y direction to the side opposite to the connection position Pw.
  • a layout similar to that of the first embodiment can be obtained by configuring the center Cc of the semiconductor laser chip 30 in the Y direction to overlap the center Cm of the covering layer 20 in the Y direction.
  • the position Pl of the light emitting portion 31 is shifted in the direction opposite to the Y direction (fourth direction) with respect to the center Cm of the coating layer 20 in the Y direction.
  • a state in which the connection position Pw is shifted in the Y direction (opposite direction to the fourth direction) with respect to the position Pl of the light emitting portion 31, that is, a state in which the moment M1 and the moment M2 cancel each other can be obtained relatively easily. be able to.
  • this embodiment similarly to the first embodiment, it is possible to suppress polarization rotation with respect to the desired characteristics.
  • FIG. 3 is a front view of the chip-on-submount 100C (100) of the third embodiment when viewed in the opposite direction of the X direction.
  • a chip-on-submount 100C of this embodiment has the same configuration as that of the first embodiment.
  • the position Pl of the light-emitting portion 31 (central axis Ax), the connection position Pw with the surface 30b of the bonding wire 50, and the position of the center Cm in the Y direction of the coating layer 20 are aligned in the Z direction. Lined up.
  • the position Pl, the connection position Pw, and the center Cm are the same position in the Y direction.
  • connection position Pw can be said to be the center-of-gravity position on which the pressing force Fw acts.
  • FIG. 4 is a front view of the chip-on-submount 100D (100) of the fourth embodiment when viewed in the opposite direction to the X direction.
  • a chip-on-submount 100D of this embodiment has the same configuration as that of the first embodiment.
  • a plurality of bonding wires 50 are mounted on the surface 30b of the semiconductor laser chip 30 symmetrically about the center Cc in the Y direction.
  • Pwc be the center of gravity of the plurality of connection positions Pw in the Y direction.
  • the position Pl of the light-emitting portion 31 (center axis Ax), the center-of-gravity position Pwc, and the position of the center Cm in the Y direction of the coating layer 20 are aligned in the Z direction.
  • the position Pl, the center-of-gravity position Pwc, and the center Cm are the same position in the Y direction.
  • the moment M1 about the central axis Ax due to the external force based on the residual stress Sc does not occur
  • the moment M2 about the central axis Ax due to the pressing force Fw (resultant force) acting from the center of gravity position Pwc also has a moment arm length of approximately 0. Therefore, the sum of the moment M1 and the moment M2 becomes substantially zero. Therefore, according to this embodiment, similarly to the above-described other embodiments, it is possible to suppress polarization rotation with respect to the desired characteristics.
  • FIG. 5 is a front view of the chip-on-submount 100E (100) of the fifth embodiment when viewed in the opposite direction of the X direction.
  • a chip-on-submount 100E of this embodiment has a configuration similar to that of the first embodiment.
  • the semiconductor laser chip 30E is a so-called ridge-type chip having a projecting portion 30c projecting from the surface 30a in the vicinity of the light emitting portion 31.
  • the light emitting portion 31 is located near the surface 30a, which is the end portion in the Z direction opposite to the center Cz in the Z direction of the semiconductor laser chip 30E, and the projecting portion 30c and the light emitting portion 31 are located in the Z direction. lined up in the direction According to research by the inventors, it has been found that such a ridge-type semiconductor laser chip 30E can also obtain the same effect by having the same configuration as the above-described other embodiments.
  • the deviation direction in the second direction with respect to the center in the second direction of the coating layer of each component or each site is not limited to the above embodiment, and may be opposite to the above embodiment.
  • the present invention can be used for chip-on-submount.
  • Submount 10 100, 100A to 100E Chip-on submount 10 Submount 10a Surface 10b Surface (first surface) 20... Coating layer 20a... Surface 20b... Surface (second surface) 30, 30B, 30E... Semiconductor laser chip (laser element) 30a surface 30b surface (third surface) 30c Projecting portion 31 Light-emitting portion 40 Bonding material 50 Bonding wire Ax Center axis Cc Center Cm Center Cz Center dc Deviation dw Deviation Fw Pressing force M1 Moment (first moment) M2... Moment (second moment) Pl: Position Pw: Connection position (pressing position) Pwc... Gravity center position Sc... Residual stress Tc... Thickness Ts... Thickness Wc... Width Wm... Width Ws... Width X... Direction (third direction) Y... direction (opposite direction to second direction and fourth direction) Z direction (first direction)

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  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
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  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)

Abstract

This chip-on-submount comprises, for example: a submount; a coating layer provided on the submount and intersecting a first direction; a laser element having a light emitting unit positioned at an intermediate portion of a second direction intersecting the first direction and outputting laser light in a third direction intersecting the first direction and the second direction; and a bonding wire that applies, to the laser element, a pressing force including a force component toward the opposite direction of the first direction. Residual stress that presses toward the center in the second direction is generated in the coating layer. A first moment, generated by the residual stress, about the central axis of the light emitting unit running along the third direction, and a second moment, generated by the pressing force acting on the laser element from the bonding wire, about the central axis of the light emitting unit cancel each other out.

Description

チップオンサブマウントChip-on-submount
　本発明は、チップオンサブマウントに関する。 The present invention relates to a chip-on-submount.
　従来、サブマウント上に導体の被覆層が設けられ、当該被覆層上にＡｕＳｎ合金などのはんだによってレーザ素子が実装された、チップオンサブマウントが知られている（例えば、特許文献１，２）。 Conventionally, there has been known a chip-on-submount in which a conductor coating layer is provided on a submount, and a laser element is mounted on the coating layer with solder such as an AuSn alloy (for example, Patent Documents 1 and 2). .
特許第５０７５１６５号公報Japanese Patent No. 5075165 特許第６９２８５６０号公報Japanese Patent No. 6928560
　この種のチップオンサブマウントにおいて、発明者らは、例えば、サブマウントに対するレーザ素子の取付位置や、レーザ素子に対するボンディングワイヤの取付位置等に応じて、レーザ素子から出力されるレーザ光に偏波回転（ずれ）が生じ、所期の光学特性が得られ難くなる場合があることを見出した。 In this type of chip-on-submount, the inventors found that, for example, depending on the mounting position of the laser element with respect to the submount, the mounting position of the bonding wire with respect to the laser element, etc., the laser light output from the laser element is polarized. It was found that rotation (misalignment) occurs, making it difficult to obtain the desired optical characteristics in some cases.
　そこで、本発明の課題の一つは、例えば、構成部品の実装によって生じる偏波回転を抑制することが可能となるような、新規な改善されたチップオンサブマウントを得ることである。 Therefore, one of the objects of the present invention is to obtain a novel and improved chip-on-submount that can, for example, suppress polarization rotation caused by mounting components.
　本発明のチップオンサブマウントは、例えば、第一方向を向いた第一面を有したサブマウントと、前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、を備え、前記被覆層には当該被覆層の前記第二方向における中央に向けて圧縮する残留応力が生じており、前記残留応力によって前記被覆層から前記レーザ素子に作用する外力によって生じる前記発光部の前記第三方向に沿う中心軸回りの第一モーメントと、前記ボンディングワイヤから前記レーザ素子に作用する前記押圧力によって生じる前記発光部の前記中心軸回りの第二モーメントと、が互いに減殺するよう構成される。 A chip-on-submount of the present invention includes, for example, a submount having a first surface facing a first direction, and a submount mounted on the first surface, extending across the first direction, and extending in the first direction. a covering layer having a second surface facing toward; a third surface mounted on said second surface and facing said first direction; a laser element that extends in a third direction that intersects the first direction and the second direction and that outputs laser light in the third direction; a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, and a residual stress that compresses the coating layer toward the center in the second direction in the coating layer. and a first moment about the central axis of the light emitting part along the third direction caused by external force acting on the laser element from the coating layer due to the residual stress, and a first moment acting on the laser element from the bonding wire. and a second moment about the central axis of the light-emitting portion generated by the pressing force to cancel each other.
　また、本発明のチップオンサブマウントは、例えば、第一方向を向いた第一面を有したサブマウントと、前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、を備え、前記被覆層には当該被覆層の前記第二方向における中央に向けて圧縮する残留応力が生じており、前記残留応力によって前記被覆層から前記レーザ素子に作用する外力によって生じる前記発光部の前記第三方向に沿う中心軸回りの第一モーメントと、前記ボンディングワイヤから前記レーザ素子に作用する前記押圧力によって生じる前記発光部の前記中心軸回りの第二モーメントと、の合計が略０である。 Also, the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction. a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction. a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; and a bonding wire that applies a pressing force including a force component directed in a direction opposite to the first direction to the laser element, and the coating layer is compressed toward the center of the coating layer in the second direction. A first moment about the central axis of the light emitting part along the third direction caused by an external force acting on the laser element from the coating layer due to the residual stress, and a first moment from the bonding wire to the laser element and a second moment about the central axis of the light-emitting portion generated by the pressing force acting on the light-emitting portion is approximately zero.
　前記チップオンサブマウントでは、前記発光部は、前記レーザ素子の前記第一方向における中央より前記第一方向の反対方向の端部の近くに位置し、前記レーザ素子は、前記発光部と前記第一方向に並び、前記第一方向の反対方向に突出した突出部を有してもよい。 In the chip-on-submount, the light-emitting section is positioned closer to the end of the laser element in the direction opposite to the first direction than the center thereof in the first direction, and the laser element includes the light-emitting section and the second mount. You may have the protrusion part which was located in a line with one direction and protruded in the opposite direction of said 1st direction.
　前記チップオンサブマウントでは、前記被覆層の前記第二方向における幅は、前記サブマウントの前記第二方向における幅より狭く、前記レーザ素子の前記第二方向における幅より広くてもよい。 In the chip-on-submount, the width of the coating layer in the second direction may be narrower than the width of the submount in the second direction and wider than the width of the laser element in the second direction.
　前記チップオンサブマウントでは、前記レーザ素子の前記第一方向における厚さは、前記サブマウントの前記第一方向における厚さの１／３以下であってもよい。 In the chip-on-submount, the thickness of the laser element in the first direction may be 1/3 or less of the thickness of the submount in the first direction.
　前記チップオンサブマウントでは、前記サブマウントは、窒化アルミニウムで作られ、前記被覆層は、銅系材料で作られてもよい。 In the chip-on-submount, the submount may be made of aluminum nitride, and the coating layer may be made of a copper-based material.
　前記チップオンサブマウントでは、前記発光部は、前記被覆層の前記第二方向における中央に対して、前記第二方向および前記第二方向の反対方向のうちの一方である第四方向にずれて位置し、前記ボンディングワイヤの前記第三面に対する押圧位置は、前記発光部に対して前記第四方向の反対方向にずれて位置してもよい。 In the chip-on-submount, the light-emitting portion is shifted in a fourth direction, which is one of the second direction and a direction opposite to the second direction, with respect to the center of the coating layer in the second direction. A pressing position of the bonding wire on the third surface may be shifted in a direction opposite to the fourth direction with respect to the light emitting portion.
　前記チップオンサブマウントでは、前記レーザ素子の前記第二方向における中央は、前記被覆層の前記第二方向における中央に対して、前記押圧位置とは反対側にずれて位置してもよい。 In the chip-on-submount, the center of the laser element in the second direction may be shifted to the side opposite to the pressing position with respect to the center of the coating layer in the second direction.
　前記チップオンサブマウントでは、前記発光部は、前記レーザ素子の前記第二方向における中央に対して、前記押圧位置とは反対側に位置してもよい。 In the chip-on-submount, the light-emitting portion may be located on the side opposite to the pressing position with respect to the center of the laser element in the second direction.
　前記チップオンサブマウントでは、前記ボンディングワイヤの前記第三面に対する押圧位置と、前記発光部の位置と、前記被覆層の前記第二方向における中央とが、前記第一方向に並んでもよい。 In the chip-on-submount, the pressing position of the bonding wire with respect to the third surface, the position of the light-emitting portion, and the center of the covering layer in the second direction may be aligned in the first direction.
　前記チップオンサブマウントでは、前記第三面には、前記ボンディングワイヤとして複数のボンディングワイヤが取り付けられ、前記複数のボンディングワイヤの前記第三面に対する押圧位置の前記第二方向における重心の位置と、前記発光部の位置と、前記被覆層の前記第二方向における中央とが、前記第一方向に並んでもよい。 In the chip-on-submount, a plurality of bonding wires are attached to the third surface as the bonding wires, and a position of a center of gravity in the second direction of pressing positions of the plurality of bonding wires against the third surface; A position of the light emitting portion and a center of the coating layer in the second direction may be aligned in the first direction.
　また、本発明のチップオンサブマウントは、例えば、第一方向を向いた第一面を有したサブマウントと、前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、を備え、前記発光部は、前記被覆層の前記第二方向における中央に対して、前記第二方向および前記第二方向の反対方向のうちの一方である第四方向にずれて位置し、前記ボンディングワイヤの前記第三面に対する押圧位置は、前記発光部に対して前記第四方向の反対方向にずれて位置する。 Also, the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction. a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction. a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; , and a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, and the light-emitting portion is positioned with respect to the center of the coating layer in the second direction, the is shifted in a fourth direction which is one of the second direction and the direction opposite to the second direction, and the pressing position of the bonding wire against the third surface is in the fourth direction with respect to the light emitting portion located in the opposite direction.
　また、本発明のチップオンサブマウントは、例えば、第一方向を向いた第一面を有したサブマウントと、前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、を備え、前記ボンディングワイヤの前記第三面に対する押圧位置の前記第二方向における重心の位置と、前記発光部と、前記被覆層の前記第二方向における中央とが、前記第一方向に並ぶ。 Also, the chip-on-submount of the present invention is, for example, a submount having a first surface facing the first direction, and is mounted on the first surface, extends across the first direction, and extends to the first direction. a covering layer having a second surface facing in one direction; a third surface mounted on the second surface and facing in the first direction; and an intermediate portion in a second direction intersecting the first direction. a laser element having a light emitting part located in the third direction and extending in a third direction intersecting the first direction and the second direction and outputting laser light in the third direction; and a bonding wire that applies a pressing force including a component force component directed in a direction opposite to the first direction to the laser element, wherein the position of the center of gravity in the second direction of the pressing position of the bonding wire on the third surface. and the light emitting portion and the center of the coating layer in the second direction are aligned in the first direction.
　本発明によれば、例えば、構成部品の取付位置に応じた偏波回転を抑制することが可能となるような、新規な改善されたチップオンサブマウントを得ることができる。 According to the present invention, it is possible to obtain a novel and improved chip-on-submount that can, for example, suppress polarization rotation according to the mounting position of the component.
図１は、第１実施形態のチップオンサブマウントの例示的かつ模式的な正面図である。FIG. 1 is an exemplary and schematic front view of the chip-on-submount of the first embodiment. 図２は、第２実施形態のチップオンサブマウントの例示的かつ模式的な正面図である。FIG. 2 is an exemplary and schematic front view of the chip-on-submount of the second embodiment. 図３は、第３実施形態のチップオンサブマウントの例示的かつ模式的な正面図である。FIG. 3 is an exemplary and schematic front view of the chip-on-submount of the third embodiment. 図４は、第４実施形態のチップオンサブマウントの例示的かつ模式的な正面図である。FIG. 4 is an exemplary and schematic front view of the chip-on-submount of the fourth embodiment. 図５は、第５実施形態のチップオンサブマウントの例示的かつ模式的な正面図である。FIG. 5 is an exemplary and schematic front view of the chip-on-submount of the fifth embodiment.
　以下、本発明の例示的な複数の実施形態が開示される。以下に示される実施形態の構成、ならびに当該構成によってもたらされる作用および結果（効果）は、一例である。本発明は、以下の実施形態に開示される構成以外によっても実現可能である。また、本発明によれば、構成によって得られる種々の効果（派生的な効果も含む）のうち少なくとも一つを得ることが可能である。 A plurality of exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments shown below and the actions and results (effects) brought about by the configurations are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. Moreover, according to the present invention, at least one of various effects (including derivative effects) obtained by the configuration can be obtained.
　以下に示される複数の実施形態は、同様の構成を備えている。よって、各実施形態の構成によれば、当該同様の構成に基づく同様の作用および効果が得られる。また、以下では、それら同様の構成には同様の符号が付与されるとともに、重複する説明が省略される場合がある。 A plurality of embodiments shown below have similar configurations. Therefore, according to the configuration of each embodiment, similar actions and effects based on the similar configuration can be obtained. Moreover, below, while the same code|symbol is provided to those same structures, the overlapping description may be abbreviate|omitted.
　また、各図において、Ｘ方向を矢印Ｘで表し、Ｙ方向を矢印Ｙで表し、Ｚ方向を矢印Ｚで表している。Ｘ方向、Ｙ方向、およびＺ方向は、互いに交差するとともに直交している。Ｘ方向は、レーザ素子からのレーザ光の出射方向であるとともに、レーザ素子の長手方向である。Ｙ方向は、レーザ素子の幅方向である。また、Ｚ方向は、サブマウント、被覆層、およびレーザ素子の積層方向であり、厚さ方向とも称される。 Also, in each figure, the X direction is indicated by an arrow X, the Y direction is indicated by an arrow Y, and the Z direction is indicated by an arrow Z. The X-, Y-, and Z-directions intersect and are orthogonal to each other. The X direction is the direction in which laser light is emitted from the laser element and the longitudinal direction of the laser element. The Y direction is the width direction of the laser element. Also, the Z direction is the stacking direction of the submount, the coating layer, and the laser element, and is also called the thickness direction.
　また、各図は、模式的なものであり、図中の寸法は実物の寸法とは異なる場合がある。 In addition, each drawing is schematic, and the dimensions in the drawing may differ from the actual dimensions.
［第１実施形態］
　図１は、第１実施形態のチップオンサブマウント１００Ａ（１００）をＸ方向の反対方向に見た場合の正面図である。図１に示されるように、チップオンサブマウント１００Ａは、サブマウント１０と、被覆層２０と、半導体レーザチップ３０と、ボンディングワイヤ５０と、を備えている。半導体レーザチップ３０は、レーザ素子の一例である。 [First embodiment]
FIG. 1 is a front view of the chip-on-submount 100A (100) of the first embodiment when viewed in the opposite direction to the X direction. As shown in FIG. 1, the chip-on-submount 100A includes a submount 10, a coating layer 20, a semiconductor laser chip 30, and bonding wires 50. As shown in FIG. The semiconductor laser chip 30 is an example of a laser element.
　サブマウント１０は、Ｚ方向における略一定の厚さで、Ｚ方向と交差しかつ直交して広がっている。サブマウント１０は、面１０ａと、当該面１０ａとは反対側の面１０ｂと、を有している。面１０ａは、Ｚ方向の反対方向を向き、Ｚ方向と交差するとともに直交している。また、面１０ｂは、Ｚ方向を向き、Ｚ方向と交差するとともに直交している。面１０ａは、裏面とも称され、面１０ｂは、表面とも称される。面１０ｂは、第一面の一例である。Ｚ方向は、第一方向の一例である。 The submount 10 has a substantially constant thickness in the Z direction and spreads across and perpendicular to the Z direction. The submount 10 has a surface 10a and a surface 10b opposite to the surface 10a. The surface 10a faces in the direction opposite to the Z direction and intersects and is orthogonal to the Z direction. Moreover, the surface 10b faces the Z direction, intersects the Z direction, and is perpendicular to the Z direction. The side 10a is also called the back side and the side 10b is also called the front side. The surface 10b is an example of a first surface. The Z direction is an example of a first direction.
　サブマウント１０の厚さは、例えば、０．３～１．０［ｍｍ］程度である。また、サブマウント１０の材料は、例えば、窒化アルミニウム（ＡｌＮ）、アルミナ（Ａｌ２Ｏ３）、べリリア（ＢｅＯ）、窒化ホウ素（ＢＮ）、ダイヤモンド、窒化ケイ素（Ｓｉ３Ｎ４）、炭化ケイ素（ＳｉＣ）、二酸化ケイ素（ＳｉＯ２）、ジルコニア（ＺｒＯ２）の少なくともいずれか一つを含みうる。窒化アルミニウム、窒化ケイ素、炭化ケイ素の熱膨張係数は、それぞれ４．５×１０－６［１／Ｋ］、２．８×１０－６［１／Ｋ］、３．７×１０－６［１／Ｋ］である。 The thickness of the submount 10 is, for example, approximately 0.3 to 1.0 [mm]. Materials for the submount 10 include, for example, aluminum nitride (AlN), alumina (Al 2 O 3 ), beryllia (BeO), boron nitride (BN), diamond, silicon nitride (Si 3 N 4 ), and silicon carbide. (SiC), silicon dioxide (SiO 2 ), and zirconia (ZrO 2 ). The thermal expansion coefficients of aluminum nitride, silicon nitride, and silicon carbide are 4.5×10 −6 [1/K], 2.8×10 −6 [1/K], and 3.7×10 −6 [1/K], respectively. /K].
　サブマウント１０の面１０ｂ上には、被覆層２０が取り付けられている。被覆層２０は、Ｚ方向における略一定の厚さで、Ｚ方向と交差しかつ直交して広がっている。被覆層２０は、面２０ａと、当該面２０ａとは反対側の面２０ｂと、を有している。面２０ａは、Ｚ方向の反対方向を向き、Ｚ方向と交差するとともに直交している。また、面２０ｂは、Ｚ方向を向き、Ｚ方向と交差するとともに直交している。面２０ａは、裏面とも称され、面２０ｂは、表面とも称される。面２０ｂは、第二面の一例である。 A coating layer 20 is attached on the surface 10b of the submount 10. The coating layer 20 has a substantially constant thickness in the Z direction and extends perpendicularly to and crossing the Z direction. The coating layer 20 has a surface 20a and a surface 20b opposite to the surface 20a. The surface 20a faces in the direction opposite to the Z direction and intersects and is orthogonal to the Z direction. In addition, the surface 20b faces the Z direction and intersects and is perpendicular to the Z direction. The side 20a is also called the back side and the side 20b is also called the front side. The surface 20b is an example of a second surface.
　被覆層２０の厚さは、例えば、２０～２００［μｍ］程度である。被覆層２０は、例えば、銅系材料で作られる。また、銅の熱膨張係数は、１７×１０－６［１／Ｋ］である。被覆層２０の熱膨張係数は、サブマウント１０の熱膨張係数よりも大きい。被覆層２０は、中間層や、被覆部材、中間部材とも称されうる。 The thickness of the coating layer 20 is, for example, approximately 20 to 200 [μm]. The covering layer 20 is made of, for example, a copper-based material. Also, the thermal expansion coefficient of copper is 17×10 −6 [1/K]. The thermal expansion coefficient of the coating layer 20 is greater than that of the submount 10 . The covering layer 20 may also be called an intermediate layer, a covering member, or an intermediate member.
　また、サブマウント１０の面１０ｂ上には、被覆層２０とは別の被覆層（不図示）も設けられている。被覆層２０と当該別の被覆層とは、いずれも上述した材料で作られた導体である。被覆層２０と当該別の被覆層とは、溝（間隔）を介して離隔され、電気的に絶縁されている。被覆層２０および当該別の被覆層は、上述した銅系材料で作られた多層膜を有している。なお、本実施形態におけるサブマウント１０を基板と称し、被覆層を含む基板（本実施形態のサブマウント１０）を、サブマウントと称する場合もある。 A coating layer (not shown) different from the coating layer 20 is also provided on the surface 10 b of the submount 10 . Both the covering layer 20 and the other covering layer are conductors made of the materials described above. The covering layer 20 and the other covering layer are separated by a groove (gap) and electrically insulated. The coating layer 20 and the other coating layer have multilayer films made of the copper-based materials described above. Note that the submount 10 in this embodiment is sometimes referred to as a substrate, and the substrate including the coating layer (the submount 10 in this embodiment) is sometimes referred to as a submount.
　被覆層２０の面２０ｂ上には、導電性を有した接合材４０を介して半導体レーザチップ３０が取り付けられている。接合材４０は、例えば、ＡｕＳｎはんだである。接合材４０は、リフロー工程において融点より高い温度に温められ、室温程度まで冷却されることで固化され、被覆層２０と半導体レーザチップ３０とを接合する。 A semiconductor laser chip 30 is mounted on the surface 20b of the coating layer 20 via a bonding material 40 having conductivity. The bonding material 40 is, for example, AuSn solder. The bonding material 40 is heated to a temperature higher than its melting point in the reflow process and solidified by being cooled down to about room temperature to bond the coating layer 20 and the semiconductor laser chip 30 together.
　半導体レーザチップ３０は、Ｚ方向における略一定の厚さで、Ｚ方向と交差しかつ直交して広がっている。半導体レーザチップ３０は、面３０ａと、当該面３０ａとは反対側の面３０ｂと、を有している。面３０ａは、Ｚ方向の反対方向を向き、Ｚ方向と交差するとともに直交している。また、面３０ｂは、Ｚ方向を向き、Ｚ方向と交差するとともに直交している。 The semiconductor laser chip 30 has a substantially constant thickness in the Z direction and spreads across and perpendicular to the Z direction. The semiconductor laser chip 30 has a surface 30a and a surface 30b opposite to the surface 30a. The surface 30a faces in the direction opposite to the Z direction and intersects and is perpendicular to the Z direction. In addition, the surface 30b faces the Z direction and intersects and is perpendicular to the Z direction.
　また、半導体レーザチップ３０は、Ｘ方向にレーザ光を出力する発光部３１を有している。発光部３１は、当該半導体レーザチップ３０のＹ方向の中間部分、本実施形態ではＹ方向における中央Ｃｃに位置し、Ｘ方向に延びている。また、発光部３１は、半導体レーザチップ３０のＺ方向における中央よりも面３０ａに近い側、具体的には、面３０ａの近傍に位置している。面３０ａは、表面とも称され、面３０ｂは、裏面とも称される。面３０ｂは、第三面の一例である。発光部３１は、活性層とも称される。また、本実施形態では、半導体レーザチップ３０は、ジャンクションダウン実装されている。なお、半導体レーザチップ３０のＹ方向の中間部分とは、半導体レーザチップ３０のうち、Ｙ方向の端部とＹ方向の反対方向の端部との間の部位を意味する。Ｙ方向は、第二方向の一例であり、Ｘ方向は、第三方向の一例である。 In addition, the semiconductor laser chip 30 has a light emitting portion 31 that outputs laser light in the X direction. The light-emitting portion 31 is positioned in the middle portion of the semiconductor laser chip 30 in the Y direction, that is, in the present embodiment, at the center Cc in the Y direction, and extends in the X direction. In addition, the light emitting portion 31 is positioned closer to the surface 30a than the center of the semiconductor laser chip 30 in the Z direction, specifically, in the vicinity of the surface 30a. The surface 30a is also referred to as the front surface and the surface 30b is also referred to as the back surface. The surface 30b is an example of a third surface. The light emitting section 31 is also called an active layer. Further, in this embodiment, the semiconductor laser chip 30 is junction-down mounted. The intermediate portion of the semiconductor laser chip 30 in the Y direction means a portion of the semiconductor laser chip 30 between the end in the Y direction and the end in the opposite Y direction. The Y direction is an example of the second direction, and the X direction is an example of the third direction.
　被覆層２０は、接合材４０を介して半導体レーザチップ３０の面３０ａに設けられた電極（例えばｐ型電極、不図示）と電気的に接続される。また、上述した面１０ｂ上の別の層は、ボンディングワイヤ５０を介して、半導体レーザチップ３０の面３０ｂ上に設けられた電極（例えばｎ型電極、不図示）と、電気的に接続されている。ボンディングワイヤ５０は、ＡｕＳｎはんだのような接合材を介して、面３０ｂ上に設けられた電極と接合されるとともに電気的に接続されている。 The coating layer 20 is electrically connected via a bonding material 40 to an electrode (for example, a p-type electrode, not shown) provided on the surface 30a of the semiconductor laser chip 30 . Another layer on the surface 10b described above is electrically connected to an electrode (for example, an n-type electrode, not shown) provided on the surface 30b of the semiconductor laser chip 30 via a bonding wire 50. there is The bonding wires 50 are joined and electrically connected to electrodes provided on the surface 30b via a joining material such as AuSn solder.
　半導体レーザチップ３０は、構成や材料に応じた波長のレーザ光を出力する。半導体レーザチップ３０の厚さは、例えば、０．１［ｍｍ］程度である。また、半導体レーザチップ３０の主成分は、例えば、ヒ化ガリウム（ＧａＡｓ）や、リン化インジウム（ＩｎＰ）である。ヒ化ガリウム、リン化インジウムの熱膨張係数は、５．９×１０－６［１／Ｋ］、４．５×１０－６［１／Ｋ］である。 The semiconductor laser chip 30 outputs a laser beam having a wavelength according to its configuration and material. The thickness of the semiconductor laser chip 30 is, for example, about 0.1 [mm]. Also, the main component of the semiconductor laser chip 30 is, for example, gallium arsenide (GaAs) or indium phosphide (InP). The thermal expansion coefficients of gallium arsenide and indium phosphide are 5.9×10 −6 [1/K] and 4.5×10 −6 [1/K].
　上記構成のチップオンサブマウント１００Ａ（１００）においては、被覆層２０の熱膨張係数が、サブマウント１０の熱膨張係数より大きく、接合材４０のリフロー工程の冷却時に、サブマウント１０より大きく収縮する。このため、被覆層２０には、図１のビュー、すなわち、チップオンサブマウント１００をＸ方向の反対方向に見た場合の正面視において、Ｙ方向における中央Ｃｍに向けて圧縮される残留応力Ｓｃが生じる。 In the chip-on-submount 100A (100) configured as described above, the coefficient of thermal expansion of the coating layer 20 is greater than that of the submount 10, so that when the bonding material 40 is cooled in the reflow process, it shrinks more than the submount 10. . Therefore, in the view of FIG. 1, that is, the front view when the chip-on-submount 100 is viewed in the direction opposite to the X direction, the coating layer 20 has a residual stress Sc that is compressed toward the center Cm in the Y direction. occurs.
　この残留応力Ｓｃは、面２０ｂおよび接合材４０を介して、半導体レーザチップ３０の面３０ａに、外力として作用する。この外力によって、発光部３１には、当該発光部３１のＸ方向に延びた中心軸Ａｘ回りのモーメントＭ１が作用する場合がある。図１の例では、発光部３１の位置Ｐｌは、被覆層２０のＹ方向における中央ＣｍからＹ方向の反対方向にずれて位置している。ここで、被覆層２０のうち、中央ＣｍよりもＹ方向の後方（図１では左方）の部位では、中央Ｃｍに向けてＹ方向へ圧縮する残留応力が生じている。よって、半導体レーザチップ３０の面３０ａのうち、発光部３１に近い、当該発光部３１に対してＺ方向の後方（図１では下方）となる部位には、Ｙ方向（図１では右方）へ向かう外力が作用する。この場合、発光部３１には、当該外力により、図１では反時計回り方向のモーメントＭ１が作用する。モーメントＭ１は、第一モーメントの一例である。また、図１の例において、Ｙ方向の反対方向は、第四方向の一例である。なお、被覆層２０のうち、中央ＣｍよりもＹ方向の前方（図１では右方）の部位では、中央Ｃｍに向けてＹ方向の反対方向へ圧縮する残留応力が生じている。 This residual stress Sc acts as an external force on the surface 30 a of the semiconductor laser chip 30 via the surface 20 b and the bonding material 40 . Due to this external force, a moment M1 about the central axis Ax of the light emitting portion 31 extending in the X direction may act on the light emitting portion 31 . In the example of FIG. 1, the position Pl of the light-emitting portion 31 is shifted in the opposite direction in the Y direction from the center Cm of the coating layer 20 in the Y direction. Here, in a portion of the coating layer 20 behind the center Cm in the Y direction (to the left in FIG. 1), a residual stress compressing the center Cm in the Y direction is generated. Therefore, on the surface 30a of the semiconductor laser chip 30, a portion near the light emitting portion 31 and behind the light emitting portion 31 in the Z direction (downward in FIG. 1) has a Y direction (rightward in FIG. 1). An external force acts toward In this case, a counterclockwise moment M1 in FIG. 1 acts on the light emitting portion 31 due to the external force. Moment M1 is an example of a first moment. Also, in the example of FIG. 1, the direction opposite to the Y direction is an example of the fourth direction. Residual stress that compresses the coating layer 20 in the opposite direction in the Y direction toward the center Cm is generated in a portion in front of the center Cm in the Y direction (to the right in FIG. 1).
　他方、上記構成のチップオンサブマウント１００Ａ（１００）においては、ボンディングワイヤ５０から、半導体レーザチップ３０を被覆層２０およびサブマウント１０に向けて押圧する押圧力Ｆｗが、作用する。押圧力Ｆｗには、Ｚ方向の反対方向（図１では下方）への分力成分が含まれている。 On the other hand, in the chip-on-submount 100A (100) configured as described above, a pressing force Fw acts from the bonding wire 50 to press the semiconductor laser chip 30 toward the covering layer 20 and the submount 10. FIG. The pressing force Fw includes a force component in the direction opposite to the Z direction (downward in FIG. 1).
　この押圧力Ｆｗによって、発光部３１には、当該発光部３１の中心軸Ａｘ回りのモーメントＭ２が作用する場合がある。図１の例では、ボンディングワイヤ５０の半導体レーザチップ３０の面３０ｂに対する押圧位置、すなわちボンディングワイヤ５０の面３０ｂとの接続位置Ｐｗは、発光部３１（中心軸Ａｘ）のＹ方向における位置Ｐｌ（本実施形態では、半導体レーザチップ３０のＹ方向における中央Ｃｃと同位置）から、ずれｄｗだけＹ方向（図１では右方）にずれて位置している。この場合、発光部３１には、当該押圧力Ｆｗにより、図１では時計回り方向のモーメントＭ２が作用する。モーメントＭ２は、第二モーメントの一例である。また、図１の例において、Ｙ方向は、第四方向の反対方向の一例である。 A moment M2 about the central axis Ax of the light emitting portion 31 may act on the light emitting portion 31 due to this pressing force Fw. In the example of FIG. 1, the pressing position of the bonding wire 50 against the surface 30b of the semiconductor laser chip 30, that is, the connection position Pw of the bonding wire 50 with the surface 30b is the position Pl ( In this embodiment, it is shifted in the Y direction (to the right in FIG. 1) by a shift dw from the center Cc of the semiconductor laser chip 30 in the Y direction). In this case, a clockwise moment M2 in FIG. 1 acts on the light emitting portion 31 due to the pressing force Fw. Moment M2 is an example of a second moment. Also, in the example of FIG. 1, the Y direction is an example of a direction opposite to the fourth direction.
　発明者らは、ボンディングワイヤ５０のＹ方向における接続位置Ｐｗに応じて、半導体レーザチップ３０から出力されるレーザ光の偏波角が変化することを見出した。具体的に、発明者らは、Ｙ方向における接続位置Ｐｗが異なる多数の半導体レーザチップ３０を作製し、半導体レーザチップ３０の中央Ｃｃに対する接続位置ＰｗのＹ方向におけるずれｄｗと、半導体レーザチップ３０の出力したレーザ光における偏波回転角（所期状態からの回転ずれ）と、の関係について、調査した。なお、ずれｄｗは、製作目標値であり、公差範囲を含む。また、ずれｄｗの符号は、接続位置Ｐｗが中央Ｃｃに対してＹ方向にずれている場合を正（＋）、Ｙ方向の反対方向にずれている場合を負（－）、とした。なお、図１の例では、半導体レーザチップ３０のＹ方向における中央Ｃｃは、発光部３１（中心軸Ａｘ）のＹ方向における位置Ｐｌである。実験結果は、以下に示すとおりとなった。
（実験結果）
ｄｗ＝＋３０［μｍ］の場合、偏波回転角：　０～　１５［ｄｅｇ］（評価：最良）
ｄｗ＝＋１５［μｍ］の場合、偏波回転角：－１０～　０［ｄｅｇ］（評価：最良）
ｄｗ＝　０［μｍ］の場合、偏波回転角：－２０～－　５［ｄｅｇ］（評価：　良）
ｄｗ＝－１５［μｍ］の場合、偏波回転角：－３０～－１０［ｄｅｇ］（評価：　可）
ｄｗ＝－３０［μｍ］の場合、偏波回転角：－５０～－３５［ｄｅｇ］（評価：不可） The inventors found that the polarization angle of the laser light output from the semiconductor laser chip 30 changes according to the connection position Pw of the bonding wire 50 in the Y direction. Specifically, the inventors manufactured a large number of semiconductor laser chips 30 having different connection positions Pw in the Y direction, and determined that the deviation dw in the Y direction of the connection position Pw from the center Cc of the semiconductor laser chip 30 and the semiconductor laser chip 30 and the polarization rotation angle (rotation deviation from the initial state) in the output laser light. Note that the deviation dw is a manufacturing target value and includes a tolerance range. The sign of the deviation dw was positive (+) when the connection position Pw was deviated in the Y direction from the center Cc, and negative (-) when deviated in the opposite direction of the Y direction. In the example of FIG. 1, the center Cc of the semiconductor laser chip 30 in the Y direction is the position Pl of the light emitting section 31 (central axis Ax) in the Y direction. The experimental results were as shown below.
(Experimental result)
When dw = +30 [μm], polarization rotation angle: 0 to 15 [deg] (evaluation: best)
When dw = +15 [μm], polarization rotation angle: -10 to 0 [deg] (evaluation: best)
When dw = 0 [μm], polarization rotation angle: -20 to -5 [deg] (evaluation: good)
When dw = -15 [μm], polarization rotation angle: -30 to -10 [deg] (evaluation: acceptable)
When dw = -30 [μm], polarization rotation angle: -50 to -35 [deg] (evaluation: not acceptable)
　実験結果より、ずれｄｗが大きくなるほど、偏波回転角が大きくなっていることが判明した。また、偏波回転角が、ｄｗ＝０の場合ではなく、ｄｗ＝＋１５～＋３０の場合に、最も小さくなっていることが判明した。発明者らの分析により、これは、発光部３１のＹ方向における位置Ｐｌが、被覆層２０のＹ方向における中央Ｃｍに対して、Ｙ方向の反対方向にずれていたから（位置Ｐｌの中央Ｃｍに対するずれ：ｄｃ、図１参照）であることが判明した。 From the experimental results, it was found that the larger the deviation dw, the larger the polarization rotation angle. It was also found that the polarization rotation angle is the smallest when dw=+15 to +30, not when dw=0. According to the analysis of the inventors, this is because the position Pl of the light emitting portion 31 in the Y direction is shifted in the opposite direction of the Y direction from the center Cm of the coating layer 20 in the Y direction (the shift of the position Pl from the center Cm : dc, see FIG. 1).
　以上より、図１の例のように、上述した残留応力Ｓｃによって生じるモーメントＭ１と、上述した押圧力Ｆｗによって生じるモーメントＭ２とが、互いに減殺するよう、チップオンサブマウント１００Ａを構成することにより、所期特性から偏波回転の小さい、光学特性の良好な半導体レーザチップ３０を得ることができたものと推定される。 As described above, as in the example of FIG. 1, by configuring the chip-on-submount 100A so that the moment M1 caused by the above-described residual stress Sc and the moment M2 caused by the above-described pressing force Fw cancel each other, From the expected characteristics, it is presumed that the semiconductor laser chip 30 with small polarization rotation and good optical characteristics could be obtained.
　また、本実施形態では、上述したように、発光部３１の位置Ｐｌが、被覆層２０のＹ方向における中央Ｃｍに対して、Ｙ方向の反対方向（第四方向）にずれて位置し、ボンディングワイヤ５０の接続位置Ｐｗが、発光部３１の位置Ｐｌに対して、Ｙ方向（第四方向の反対方向）にずれて位置することで、所期特性に対する偏波回転を抑制することができた。 Further, in the present embodiment, as described above, the position Pl of the light emitting portion 31 is shifted in the direction opposite to the Y direction (fourth direction) with respect to the center Cm of the coating layer 20 in the Y direction, and bonding By displacing the connection position Pw of the wire 50 in the Y direction (opposite direction to the fourth direction) with respect to the position Pl of the light emitting section 31, it was possible to suppress the polarization rotation with respect to the desired characteristics. .
　さらに、本実施形態では、発光部３１（中心軸Ａｘ）が、半導体レーザチップ３０のＹ方向における中央Ｃｃに位置しているため、当該中央Ｃｃが、被覆層２０のＹ方向における中央Ｃｍに対して、接続位置Ｐｗとは反対側にずれることで、所期特性に対する偏波回転を抑制することができた。 Furthermore, in the present embodiment, the light-emitting portion 31 (central axis Ax) is positioned at the center Cc of the semiconductor laser chip 30 in the Y direction. By shifting to the side opposite to the connection position Pw, it was possible to suppress the polarization rotation with respect to the desired characteristics.
　また、発明者らの研究により、このような構成による偏波回転角の減少効果は、被覆層２０のＹ方向における幅Ｗｍが、サブマウント１０のＹ方向における幅Ｗｓより狭く、半導体レーザチップ３０の幅Ｗｃより広い場合に得られ、特に、幅Ｗｍと幅Ｗｓとの差（Ｗｓ－Ｗｍ）が、幅Ｗｓの１／２以下である場合に好ましく、幅Ｗｓの１／３以下である場合により好ましいことが判明した。また、半導体レーザチップ３０のＺ方向における厚さＴｃは、サブマウント１０のＺ方向における厚さＴｓの１／３以下であるのが好ましいことが判明した。 Further, according to research by the inventors, the effect of reducing the polarization rotation angle by such a configuration is that the width Wm of the coating layer 20 in the Y direction is narrower than the width Ws of the submount 10 in the Y direction, and the semiconductor laser chip 30 In particular, the difference between the width Wm and the width Ws (Ws-Wm) is preferably 1/2 or less of the width Ws, and 1/3 or less of the width Ws was found to be more favorable. It has also been found that the thickness Tc of the semiconductor laser chip 30 in the Z direction is preferably ⅓ or less of the thickness Ts of the submount 10 in the Z direction.
［第２実施形態］
　図２は、第２実施形態のチップオンサブマウント１００Ｂ（１００）をＸ方向の反対方向に見た場合の正面図である。 [Second embodiment]
FIG. 2 is a front view of the chip-on-submount 100B (100) of the second embodiment when viewed in the opposite direction to the X direction.
　本実施形態のチップオンサブマウント１００Ｂは、上記第１実施形態と同様の構成を備えている。ただし、本実施形態では、半導体レーザチップ３０Ｂ内での発光部３１のＹ方向における位置Ｐｌが、上記第１実施形態とは相違している。すなわち、本実施形態では、半導体レーザチップ３０Ｂにおいて、発光部３１（中心軸Ａｘ）は、半導体レーザチップ３０のＹ方向における中央Ｃｃに対して、接続位置Ｐｗとは反対側にずれて位置している。この場合、半導体レーザチップ３０のＹ方向における中央Ｃｃが、被覆層２０のＹ方向における中央Ｃｍと重なるよう構成することにより、上記第１実施形態と同様のレイアウトを得ることができる。すなわち、本実施形態によれば、発光部３１の位置Ｐｌが、被覆層２０のＹ方向における中央Ｃｍに対して、Ｙ方向の反対方向（第四方向）にずれて位置し、ボンディングワイヤ５０の接続位置Ｐｗが発光部３１の位置Ｐｌに対して、Ｙ方向（第四方向の反対方向）にずれて位置する状態、すなわち、モーメントＭ１とモーメントＭ２とが減殺する状態を、比較的容易に得ることができる。本実施形態によっても、上記第１実施形態と同様、所期特性に対する偏波回転を抑制することができる。 A chip-on-submount 100B of this embodiment has the same configuration as that of the first embodiment. However, in the present embodiment, the position Pl of the light emitting section 31 in the Y direction within the semiconductor laser chip 30B is different from that in the first embodiment. That is, in the present embodiment, in the semiconductor laser chip 30B, the light emitting portion 31 (central axis Ax) is shifted from the center Cc of the semiconductor laser chip 30 in the Y direction to the side opposite to the connection position Pw. there is In this case, a layout similar to that of the first embodiment can be obtained by configuring the center Cc of the semiconductor laser chip 30 in the Y direction to overlap the center Cm of the covering layer 20 in the Y direction. That is, according to the present embodiment, the position Pl of the light emitting portion 31 is shifted in the direction opposite to the Y direction (fourth direction) with respect to the center Cm of the coating layer 20 in the Y direction. A state in which the connection position Pw is shifted in the Y direction (opposite direction to the fourth direction) with respect to the position Pl of the light emitting portion 31, that is, a state in which the moment M1 and the moment M2 cancel each other can be obtained relatively easily. be able to. According to this embodiment, similarly to the first embodiment, it is possible to suppress polarization rotation with respect to the desired characteristics.
［第３実施形態］
　図３は、第３実施形態のチップオンサブマウント１００Ｃ（１００）をＸ方向の反対方向に見た場合の正面図である。 [Third embodiment]
FIG. 3 is a front view of the chip-on-submount 100C (100) of the third embodiment when viewed in the opposite direction of the X direction.
　本実施形態のチップオンサブマウント１００Ｃは、上記第１実施形態と同様の構成を備えている。ただし、本実施形態では、発光部３１（中心軸Ａｘ）の位置Ｐｌと、ボンディングワイヤ５０の面３０ｂとの接続位置Ｐｗと、被覆層２０のＹ方向における中央Ｃｍの位置とが、Ｚ方向に並んでいる。言い換えると、位置Ｐｌ、接続位置Ｐｗ、および中央Ｃｍが、Ｙ方向においては同じ位置である。この場合、残留応力Ｓｃに基づく外力による中心軸Ａｘ回りのモーメントＭ１が生じず、また、接続位置Ｐｗから作用する押圧力Ｆｗによる中心軸Ａｘ回りのモーメントＭ２もモーメントアームの長さが略０となるため生じず、モーメントＭ１とモーメントＭ２との合計が略０となる。したがって、本実施形態によっても、上記他の実施形態と同様、所期特性に対する偏波回転を抑制することができる。なお、本実施形態では、接続位置Ｐｗは、押圧力Ｆｗが作用する重心位置と言うことができる。 A chip-on-submount 100C of this embodiment has the same configuration as that of the first embodiment. However, in the present embodiment, the position Pl of the light-emitting portion 31 (central axis Ax), the connection position Pw with the surface 30b of the bonding wire 50, and the position of the center Cm in the Y direction of the coating layer 20 are aligned in the Z direction. Lined up. In other words, the position Pl, the connection position Pw, and the center Cm are the same position in the Y direction. In this case, the moment M1 about the central axis Ax due to the external force based on the residual stress Sc does not occur, and the length of the moment arm of the moment M2 about the central axis Ax due to the pressing force Fw acting from the connection position Pw is substantially zero. Therefore, the sum of the moment M1 and the moment M2 becomes substantially zero. Therefore, according to this embodiment, similarly to the above-described other embodiments, it is possible to suppress polarization rotation with respect to the desired characteristics. In addition, in this embodiment, the connection position Pw can be said to be the center-of-gravity position on which the pressing force Fw acts.
［第４実施形態］
　図４は、第４実施形態のチップオンサブマウント１００Ｄ（１００）をＸ方向の反対方向に見た場合の正面図である。 [Fourth embodiment]
FIG. 4 is a front view of the chip-on-submount 100D (100) of the fourth embodiment when viewed in the opposite direction to the X direction.
　本実施形態のチップオンサブマウント１００Ｄは、上記第１実施形態と同様の構成を備えている。ただし、本実施形態では、半導体レーザチップ３０の面３０ｂ上には、Ｙ方向における中央Ｃｃを対称として複数のボンディングワイヤ５０が実装されている。複数の接続位置ＰｗのＹ方向における重心位置をＰｗｃとする。そして、本実施形態では、発光部３１（中心軸Ａｘ）の位置Ｐｌと、重心位置Ｐｗｃと、被覆層２０のＹ方向における中央Ｃｍの位置とが、Ｚ方向に並んでいる。言い換えると、位置Ｐｌ、重心位置Ｐｗｃ、および中央Ｃｍが、Ｙ方向においては同じ位置である。この場合、残留応力Ｓｃに基づく外力による中心軸Ａｘ回りのモーメントＭ１が生じず、重心位置Ｐｗｃから作用する押圧力Ｆｗ（合力）による中心軸Ａｘ回りのモーメントＭ２もモーメントアームの長さが略０となるため生じず、モーメントＭ１とモーメントＭ２との合計が略０となる。したがって、本実施形態によっても、上記他の実施形態と同様、所期特性に対する偏波回転を抑制することができる。 A chip-on-submount 100D of this embodiment has the same configuration as that of the first embodiment. However, in this embodiment, a plurality of bonding wires 50 are mounted on the surface 30b of the semiconductor laser chip 30 symmetrically about the center Cc in the Y direction. Let Pwc be the center of gravity of the plurality of connection positions Pw in the Y direction. In this embodiment, the position Pl of the light-emitting portion 31 (center axis Ax), the center-of-gravity position Pwc, and the position of the center Cm in the Y direction of the coating layer 20 are aligned in the Z direction. In other words, the position Pl, the center-of-gravity position Pwc, and the center Cm are the same position in the Y direction. In this case, the moment M1 about the central axis Ax due to the external force based on the residual stress Sc does not occur, and the moment M2 about the central axis Ax due to the pressing force Fw (resultant force) acting from the center of gravity position Pwc also has a moment arm length of approximately 0. Therefore, the sum of the moment M1 and the moment M2 becomes substantially zero. Therefore, according to this embodiment, similarly to the above-described other embodiments, it is possible to suppress polarization rotation with respect to the desired characteristics.
［第５実施形態］
　図５は、第５実施形態のチップオンサブマウント１００Ｅ（１００）をＸ方向の反対方向に見た場合の正面図である。 [Fifth embodiment]
FIG. 5 is a front view of the chip-on-submount 100E (100) of the fifth embodiment when viewed in the opposite direction of the X direction.
　本実施形態のチップオンサブマウント１００Ｅは、上記第１実施形態と同様の構成を備えている。ただし、本実施形態では、半導体レーザチップ３０Ｅは、発光部３１の近傍において、面３０ａから突出した突出部３０ｃを有した、所謂リッジ型のチップである。この場合、発光部３１は、半導体レーザチップ３０ＥのＺ方向における中央ＣｚよりＺ方向の反対方向の端部である面３０ａの近くに位置するとともに、突出部３０ｃと、発光部３１とが、Ｚ方向に並んでいる。発明者らの研究により、このようなリッジ型の半導体レーザチップ３０Ｅにおいても、上記他の実施形態と同様の構成を備えることにより、同様の効果が得られることが判明した。 A chip-on-submount 100E of this embodiment has a configuration similar to that of the first embodiment. However, in this embodiment, the semiconductor laser chip 30E is a so-called ridge-type chip having a projecting portion 30c projecting from the surface 30a in the vicinity of the light emitting portion 31. FIG. In this case, the light emitting portion 31 is located near the surface 30a, which is the end portion in the Z direction opposite to the center Cz in the Z direction of the semiconductor laser chip 30E, and the projecting portion 30c and the light emitting portion 31 are located in the Z direction. lined up in the direction According to research by the inventors, it has been found that such a ridge-type semiconductor laser chip 30E can also obtain the same effect by having the same configuration as the above-described other embodiments.
　以上、本発明の実施形態が例示されたが、上記実施形態は一例であって、発明の範囲を限定することは意図していない。上記実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、組み合わせ、変更を行うことができる。また、各構成や、形状、等のスペック（構造や、種類、方向、型式、大きさ、長さ、幅、厚さ、高さ、数、配置、位置、材質等）は、適宜に変更して実施することができる。 Although the embodiment of the present invention has been illustrated above, the above embodiment is an example and is not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, replacements, combinations, and modifications can be made without departing from the scope of the invention. In addition, specifications such as each configuration and shape (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) may be changed as appropriate. can be implemented.
　例えば、各構成部品や各部位の被覆層の第二方向における中央に対する当該第二方向におけるずれ方向は、上記実施形態には限定されず、上記実施形態とは逆であってもよい。 For example, the deviation direction in the second direction with respect to the center in the second direction of the coating layer of each component or each site is not limited to the above embodiment, and may be opposite to the above embodiment.
　本発明は、チップオンサブマウントに利用することができる。 The present invention can be used for chip-on-submount.
１００，１００Ａ～１００Ｅ…チップオンサブマウント
１０…サブマウント
１０ａ…面
１０ｂ…面（第一面）
２０…被覆層
２０ａ…面
２０ｂ…面（第二面）
３０，３０Ｂ，３０Ｅ…半導体レーザチップ（レーザ素子）
３０ａ…面
３０ｂ…面（第三面）
３０ｃ…突出部
３１…発光部
４０…接合材
５０…ボンディングワイヤ
Ａｘ…中心軸
Ｃｃ…中央
Ｃｍ…中央
Ｃｚ…中央
ｄｃ…ずれ
ｄｗ…ずれ
Ｆｗ…押圧力
Ｍ１…モーメント（第一モーメント）
Ｍ２…モーメント（第二モーメント）
Ｐｌ…位置
Ｐｗ…接続位置（押圧位置）
Ｐｗｃ…重心位置
Ｓｃ…残留応力
Ｔｃ…厚さ
Ｔｓ…厚さ
Ｗｃ…幅
Ｗｍ…幅
Ｗｓ…幅
Ｘ…方向（第三方向）
Ｙ…方向（第二方向、第四方向の反対方向）
Ｚ…方向（第一方向） 100, 100A to 100E Chip-on submount 10 Submount 10a Surface 10b Surface (first surface)
20... Coating layer 20a... Surface 20b... Surface (second surface)
30, 30B, 30E... Semiconductor laser chip (laser element)
30a surface 30b surface (third surface)
30c Projecting portion 31 Light-emitting portion 40 Bonding material 50 Bonding wire Ax Center axis Cc Center Cm Center Cz Center dc Deviation dw Deviation Fw Pressing force M1 Moment (first moment)
M2... Moment (second moment)
Pl: Position Pw: Connection position (pressing position)
Pwc... Gravity center position Sc... Residual stress Tc... Thickness Ts... Thickness Wc... Width Wm... Width Ws... Width X... Direction (third direction)
Y... direction (opposite direction to second direction and fourth direction)
Z direction (first direction)

Claims (13)

  1. 　第一方向を向いた第一面を有したサブマウントと、
    　前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、
    　前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、
    　前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、
    　を備え、
    　前記被覆層には当該被覆層の前記第二方向における中央に向けて圧縮する残留応力が生じており、
    　前記残留応力によって前記被覆層から前記レーザ素子に作用する外力によって生じる前記発光部の前記第三方向に沿う中心軸回りの第一モーメントと、前記ボンディングワイヤから前記レーザ素子に作用する前記押圧力によって生じる前記発光部の前記中心軸回りの第二モーメントと、が互いに減殺するよう構成された、チップオンサブマウント。     a submount having a first surface facing the first direction;
    a covering layer mounted on the first surface and extending across the first direction and having a second surface facing the first direction;
    A third surface mounted on the second surface and facing the first direction; a laser element having a light emitting part extending in three directions and outputting laser light in the third direction;
    a bonding wire attached to the third surface and applying a pressing force including a component force component directed in a direction opposite to the first direction to the laser element;
    with
    Residual stress compressing the coating layer toward the center in the second direction is generated in the coating layer,
    A first moment about the central axis of the light emitting section along the third direction caused by an external force acting on the laser element from the coating layer due to the residual stress, and the pressing force acting on the laser element from the bonding wire and a second moment about the central axis of the light-emitting portion that is generated cancel each other out.
  2. 　第一方向を向いた第一面を有したサブマウントと、
    　前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、
    　前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、
    　前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、
    　を備え、
    　前記被覆層には当該被覆層の前記第二方向における中央に向けて圧縮する残留応力が生じており、
    　前記残留応力によって前記被覆層から前記レーザ素子に作用する外力によって生じる前記発光部の前記第三方向に沿う中心軸回りの第一モーメントと、前記ボンディングワイヤから前記レーザ素子に作用する前記押圧力によって生じる前記発光部の前記中心軸回りの第二モーメントと、の合計が略０である、チップオンサブマウント。     a submount having a first surface facing the first direction;
    a covering layer mounted on the first surface and extending across the first direction and having a second surface facing the first direction;
    A third surface mounted on the second surface and facing the first direction; a laser element having a light emitting part extending in three directions and outputting laser light in the third direction;
    a bonding wire attached to the third surface and applying a pressing force including a component force component directed in a direction opposite to the first direction to the laser element;
    with
    Residual stress compressing the coating layer toward the center in the second direction is generated in the coating layer,
    A first moment about the central axis of the light emitting section along the third direction caused by an external force acting on the laser element from the coating layer due to the residual stress, and the pressing force acting on the laser element from the bonding wire and a second moment about the central axis of the light-emitting portion, the sum of which is substantially zero.
  3. 　前記発光部は、前記レーザ素子の前記第一方向における中央より前記第一方向の反対方向の端部の近くに位置し、
    　前記レーザ素子は、前記発光部と前記第一方向に並び、前記第一方向の反対方向に突出した突出部を有した、請求項１または２に記載のチップオンサブマウント。     the light emitting unit is positioned closer to the end of the laser element in the first direction than the center of the laser element in the first direction;
    3. The chip-on-submount according to claim 1, wherein said laser element has a protruding portion aligned in said first direction with said light emitting portion and protruding in a direction opposite to said first direction.
  4. 　前記被覆層の前記第二方向における幅は、前記サブマウントの前記第二方向における幅よりも狭く、前記レーザ素子の前記第二方向における幅よりも広い、請求項１～３のうちいずれか一つに記載のチップオンサブマウント。 The width of the coating layer in the second direction is narrower than the width of the submount in the second direction and wider than the width of the laser element in the second direction. Chip-on-submount described in one.
  5. 　前記レーザ素子の前記第一方向における厚さは、前記サブマウントの前記第一方向における厚さの１／３以下である、請求項１～４のうちいずれか一つに記載のチップオンサブマウント。 The chip-on-submount according to any one of claims 1 to 4, wherein the thickness of the laser element in the first direction is ⅓ or less of the thickness of the submount in the first direction. .
  6. 　前記サブマウントは、窒化アルミニウムで作られ、
    　前記被覆層は、銅系材料で作られた、請求項１～５のうちいずれか一つに記載のチップオンサブマウント。     the submount is made of aluminum nitride,
    The chip-on-submount according to any one of claims 1 to 5, wherein said coating layer is made of a copper-based material.
  7. 　前記発光部は、前記被覆層の前記第二方向における中央に対して、前記第二方向および前記第二方向の反対方向のうちの一方である第四方向にずれて位置し、
    　前記ボンディングワイヤの前記第三面に対する押圧位置は、前記発光部に対して前記第四方向の反対方向にずれて位置した、請求項１～６のうちいずれか一つに記載のチップオンサブマウント。     the light-emitting portion is shifted in a fourth direction, which is one of the second direction and a direction opposite to the second direction, with respect to the center of the coating layer in the second direction;
    7. The chip-on-submount according to claim 1, wherein a pressing position of said bonding wire against said third surface is shifted in a direction opposite to said fourth direction with respect to said light emitting part. .
  8. 　前記レーザ素子の前記第二方向における中央は、前記被覆層の前記第二方向における中央に対して、前記押圧位置とは反対側にずれて位置した、請求項７に記載のチップオンサブマウント。 8. The chip-on-submount according to claim 7, wherein the center of the laser element in the second direction is shifted from the center of the coating layer in the second direction to the side opposite to the pressing position.
  9. 　前記発光部は、前記レーザ素子の前記第二方向における中央に対して、前記押圧位置とは反対側に位置した、請求項７に記載のチップオンサブマウント。 The chip-on-submount according to claim 7, wherein the light-emitting portion is located on the side opposite to the pressing position with respect to the center of the laser element in the second direction.
  10. 　前記ボンディングワイヤの前記第三面に対する押圧位置と、前記発光部の位置と、前記被覆層の前記第二方向における中央とが、前記第一方向に並んだ、請求項１～６のうちいずれか一つに記載のチップオンサブマウント。 Any one of claims 1 to 6, wherein the pressing position of the bonding wire against the third surface, the position of the light emitting part, and the center of the coating layer in the second direction are aligned in the first direction. Chip-on-submount described in one.
  11. 　前記第三面には、前記ボンディングワイヤとして複数のボンディングワイヤが取り付けられ、
    　前記複数のボンディングワイヤの前記第三面に対する押圧位置の前記第二方向における重心の位置と、前記発光部の位置と、前記被覆層の前記第二方向における中央とが、前記第一方向に並んだ、請求項１～６のうちいずれか一つに記載のチップオンサブマウント。     A plurality of bonding wires are attached to the third surface as the bonding wires,
    The position of the center of gravity in the second direction of the pressing positions of the plurality of bonding wires against the third surface, the position of the light emitting section, and the center of the coating layer in the second direction are aligned in the first direction. A chip-on-submount according to any one of claims 1 to 6.
  12. 　第一方向を向いた第一面を有したサブマウントと、
    　前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、
    　前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、
    　前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、
    　を備え、
    　前記発光部は、前記被覆層の前記第二方向における中央に対して、前記第二方向および前記第二方向の反対方向のうちの一方である第四方向にずれて位置し、
    　前記ボンディングワイヤの前記第三面に対する押圧位置は、前記発光部に対して前記第四方向の反対方向にずれて位置した、チップオンサブマウント。     a submount having a first surface facing the first direction;
    a covering layer mounted on the first surface and extending across the first direction and having a second surface facing the first direction;
    A third surface mounted on the second surface and facing the first direction; a laser element having a light emitting part extending in three directions and outputting laser light in the third direction;
    a bonding wire attached to the third surface and applying a pressing force including a component force component directed in a direction opposite to the first direction to the laser element;
    with
    the light-emitting portion is shifted in a fourth direction, which is one of the second direction and a direction opposite to the second direction, with respect to the center of the coating layer in the second direction;
    A chip-on-submount, wherein a pressing position of the bonding wire against the third surface is shifted in a direction opposite to the fourth direction with respect to the light-emitting portion.
  13. 　第一方向を向いた第一面を有したサブマウントと、
    　前記第一面上に取り付けられ、前記第一方向と交差して広がり、前記第一方向を向いた第二面を有した、被覆層と、
    　前記第二面上に取り付けられ、前記第一方向を向いた第三面と、前記第一方向と交差した第二方向の中間部分に位置し前記第一方向および前記第二方向と交差した第三方向に延びるとともに当該第三方向にレーザ光を出力する発光部と、を有したレーザ素子と、
    　前記第三面上に取り付けられ、前記レーザ素子に前記第一方向の反対方向に向かう分力成分を含む押圧力を与えるボンディングワイヤと、
    　を備え、
    　前記ボンディングワイヤの前記第三面に対する押圧位置の前記第二方向における重心の位置と、前記発光部と、前記被覆層の前記第二方向における中央とが、前記第一方向に並んだ、
    　チップオンサブマウント。     a submount having a first surface facing the first direction;
    a covering layer mounted on the first surface and extending across the first direction and having a second surface facing the first direction;
    A third surface mounted on the second surface and facing the first direction; a laser element having a light emitting part extending in three directions and outputting laser light in the third direction;
    a bonding wire attached to the third surface and applying a pressing force including a component force component directed in a direction opposite to the first direction to the laser element;
    with
    The position of the center of gravity in the second direction of the pressing position of the bonding wire with respect to the third surface, the light emitting portion, and the center of the coating layer in the second direction are aligned in the first direction,
    Chip-on-submount.
PCT/JP2022/023669 2021-06-15 2022-06-13 Chip-on-submount WO2022264972A1 (en)

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JP2023529864A JPWO2022264972A1 (en) 2021-06-15 2022-06-13
CN202280040982.XA CN117461225A (en) 2021-06-15 2022-06-13 Chip-on-base package
US18/534,857 US20240106189A1 (en) 2022-02-08 2023-12-11 Chip on submount

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US202163210704P 2021-06-15 2021-06-15
US63/210,704 2021-06-15
JP2022018254 2022-02-08
JP2022-018254 2022-02-08

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002261376A (en) * 2001-03-02 2002-09-13 Sharp Corp Semiconductor light emitting device
JP2004140052A (en) * 2002-10-16 2004-05-13 Sanyo Electric Co Ltd Electrode structure and its fabricating process
JP2012054474A (en) * 2010-09-02 2012-03-15 Opnext Japan Inc Semiconductor laser device
JP2014022481A (en) * 2012-07-17 2014-02-03 Japan Oclaro Inc Multi-beam semiconductor laser device
JP2017017297A (en) * 2015-07-07 2017-01-19 株式会社リコー Semiconductor device and laser equipment
WO2017138666A1 (en) * 2016-02-12 2017-08-17 古河電気工業株式会社 Submount, submount having semiconductor element mounted thereto, and semiconductor element module
US20190044302A1 (en) * 2017-08-02 2019-02-07 Nlight, Inc. Cte-matched silicon-carbide submount with high thermal conductivity contacts

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002261376A (en) * 2001-03-02 2002-09-13 Sharp Corp Semiconductor light emitting device
JP2004140052A (en) * 2002-10-16 2004-05-13 Sanyo Electric Co Ltd Electrode structure and its fabricating process
JP2012054474A (en) * 2010-09-02 2012-03-15 Opnext Japan Inc Semiconductor laser device
JP2014022481A (en) * 2012-07-17 2014-02-03 Japan Oclaro Inc Multi-beam semiconductor laser device
JP2017017297A (en) * 2015-07-07 2017-01-19 株式会社リコー Semiconductor device and laser equipment
WO2017138666A1 (en) * 2016-02-12 2017-08-17 古河電気工業株式会社 Submount, submount having semiconductor element mounted thereto, and semiconductor element module
US20190044302A1 (en) * 2017-08-02 2019-02-07 Nlight, Inc. Cte-matched silicon-carbide submount with high thermal conductivity contacts

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