JP2015219436A - Optical module manufacturing method and optical module manufacturing apparatus - Google Patents

Abstract

An optical module manufacturing method and an optical module manufacturing apparatus capable of performing mounting while preventing warping of a chip are provided. A method of manufacturing an optical module in which a chip 40 in which an active region for realizing a predetermined function is provided at least in a peripheral region of a predetermined edge 42a of a chip surface 42 is mounted on an insulating substrate. The step of adsorbing the range 44c excluding the active area on the chip surface, the step of contacting the edge located on the back surface of the chip facing the predetermined edge with the surface of the insulating substrate, and bringing the entire chip back surface into contact with the surface of the insulating substrate Steps. [Selection] Figure 3

Description

  The present invention relates to an optical module manufacturing method and an optical module manufacturing apparatus for mounting a chip on an insulating substrate.

  An electronic circuit or the like is integrated on a crystal piece (also referred to as a die) such as a chip, and the chip separated from the wafer is mounted on a lead frame or a package (also referred to as die bonding). With respect to die bonding, for example, Patent Document 1 discloses a technique for adsorbing the edge of a chip surface with a vacuum collet and mounting the chip by moving the chip to a predetermined position.

  Adsorption by a collet is also used for die bonding of an optical device having a photoelectric conversion function. For example, an edge-emitting semiconductor laser (LD) or an edge-receiving photodiode (PD) is used. ), Since the end face of the chip greatly affects the characteristics, it is not preferable to adsorb the edge of the chip surface. In this case, for example, it is conceivable to use a technique for adsorbing the chip surface as in Patent Documents 1 and 2.

JP 2003-264202 A JP 2006-114831 A

  By the way, when the chip has a thickness of, for example, about 0.1 mm, it is inappropriate to suck the edge of the chip surface as in Patent Document 1, but if the chip surface is sucked as in Patent Documents 1 and 2, When the chip is mounted on the insulating substrate, the warp of the chip cannot be prevented, and there is a problem that the edge of the back surface of the chip is lifted from the surface of the insulating substrate and mounted.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical module manufacturing method and an optical module manufacturing apparatus capable of implementing a mount that prevents chip warpage.

  An optical module manufacturing method according to an aspect of the present invention is an optical module manufacturing method in which a chip provided with an active region for realizing a predetermined function at least in a peripheral region of a predetermined edge of a chip surface is mounted on an insulating substrate. A step of adsorbing a range of the chip surface excluding the active region, a step of contacting an edge located on the chip back surface facing the predetermined edge with the surface of the insulating substrate, and the entire chip back surface Contacting the surface of the insulating substrate.

  Based on the above, it is possible to implement a mount that prevents chip warpage.

It is a structural diagram showing an example of an optical module according to the present invention. FIG. 2 is a perspective view of the chip of FIG. 1 and an insulating substrate on which the chip is mounted. It is a front view of the chip | tip of FIG. It is a figure explaining 1st Embodiment of this invention. FIG. 5 is a cross-sectional view of FIG. 4. It is a figure explaining 2nd Embodiment of this invention.

[Details of the embodiment of the present invention]
Hereinafter, a specific example of an optical module manufacturing method and an optical module manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included.
FIG. 1 is a structural diagram showing an example of an optical module according to the present invention. The optical module 1 is, for example, a small coherent optical receiver, and processes such as polarization separation and phase separation are performed in order to separate individual signals from input light obtained by multiplexing signals.

The optical module 1 has a rectangular package 2, and two of received signal light (Signal, hereinafter, signal light) and local oscillation light (Local, hereinafter, local light) are packaged from one side of the package 2. It is input inside. In addition, a plurality of output terminals 3 that are electrically connected to, for example, a connector of a host device (not shown) are provided on the other side surface of the package 2.
The signal light side has the same structure as a conventional receiving optical sub-assembly (ROSA), and accommodates a sleeve 6 that receives the ferrule 5 of the single mode fiber 4, a joint sleeve 7 that holds the sleeve 6, and a condenser lens 9. The lens holder 8 is fixed to one side surface of the package 2.

The lens holder 8 slides the joint sleeve 7 in the XY direction (perpendicular to the optical axis) to perform optical alignment in the XY plane, and changes the holding length of the sleeve 6 by the joint sleeve 7 to change the Z direction (light (Axial direction) optical alignment. The signal light collected by the condenser lens 9 is emitted toward the inside of the package 2.
On the metal base 2a in the package 2, an optical component that performs polarization separation processing, an optical device that performs phase separation processing (hereinafter referred to as a chip), and the like are provided.

  Specifically, the structure on the signal light side includes a VOA (Variable Optical Attenuator) 20, a collimator lens 21, a beam splitter 22, a power monitor PD 23, a polarization beam splitter 24, a skew adjustment element 25, condenser lenses 26 and 29, A mirror 28 is provided. The signal light side is formed by three lenses including a condensing lens 9, a collimating lens 21, and condensing lenses 26 and 29, and ensures the opening of the VOA 20 and from the end of the single mode fiber 4 to the end of a chip 40 to be described later. Ensuring coupling efficiency up to.

  The signal light collected by the condenser lens 9 passes through the VOA 20 and is converted into collimated light by the collimator lens 21. The signal light converted into collimated light is branched by the beam splitter 22 into light directed to the power monitor PD 23 and light directed to the polarization beam splitter 24. Note that the branching ratio to the power monitor PD 23 is less than 10%. When an over-input state is detected by the PD 23, the attenuation of the VOA 20 can be increased to block the signal light.

The signal light traveling toward the polarization beam splitter 24 is separated into light traveling straight through the polarization beam splitter 24 toward the one chip 40 and light traveling toward the other chip 40 after being bent by 90 ° ( Branching ratio 50%).
The signal light that has traveled straight by the polarization beam splitter 24 is compensated by the skew adjusting element 25 for the time of the signal light that travels toward the other chip 40, and then collected by, for example, a two-stage condenser lens 26 and reaches one chip 40. To do.

The signal light bent by 90 ° by the polarization beam splitter 24 is again bent by 90 ° by the mirror 28, and then collected by, for example, a two-stage condenser lens 29 and reaches the other chip 40.
On the other hand, the local light emitting side has sleeves 12 and 13 that receive the ferrule 11 of the polarization maintaining fiber 10 and a lens holder 14 that holds the sleeve 13 and accommodates the collimating lens 15. The lens holder 14 is the package 2. It is fixed on one side.

Local light from a local light source (not shown) whose polarization direction is maintained by the polarization maintaining fiber 19 is converted into collimated light by the collimator lens 15 and then emitted toward the inside of the package 2.
The local light emission side structure includes a polarizer 30, a beam splitter 31, a skew adjustment element 32, condenser lenses 33 and 36, a half-wave plate 34, and a mirror 35.

The polarization direction of the local light converted into the collimated light is determined by the polarizer 30. Thereby, even if the deflection direction maintained by the polarization maintaining fiber 19 is shifted when the package 2 is assembled, the deflection direction can be determined to be 0 ° or 90 °.
The local light whose deflection direction is determined is branched into light directed to one chip 40 after being bent by 90 ° by the beam splitter 31 and light directed straight to the other chip 40 (branch ratio 50%). .

The local light that has been bent by 90 ° by the beam splitter 31 is changed by 90 ° with respect to the local light that has traveled straight by the beam splitter 31 by the half-wave plate 34, and is again bent by 90 ° by the mirror 35. The light is collected by the two-stage condenser lens 36 and reaches one chip 40.
The local light that travels straight by the beam splitter 31 is collected by, for example, a two-stage condenser lens 33 and reaches the other chip 40 after compensating the time of local light toward the one chip 40 by the skew adjusting element 32.

As described above, the signal light and the local light emitted to the inside of the package 2 are distributed and input to the two chips 40.
Each chip 40 is, for example, a PD integrated MMI chip. The photocurrent generated by the PD of the chip 40 is linearly converted into a voltage signal by the amplifier 50, output from the output terminal 3 to, for example, a host device, and signal-processed by the electric circuit.

FIG. 2 is a perspective view of the chip of FIG. 1 and an insulating substrate on which the chip is mounted, and FIG. 3 is a front view of the chip of FIG.
The chip 40 includes a chip body 41 made of, for example, semi-insulating InP (indium phosphide). The chip body 41 is provided with a chip surface 42 of about 1.6 mm × 4.1 mm, for example, and a chip back surface 43 described with reference to FIG. 6, and is formed in a thin plate shape with a thickness of about 0.1 mm, for example.

  As shown in FIG. 2, the chip 40 is mounted on, for example, a ceramic insulating substrate 81 (also referred to as a carrier substrate), and the chip back surface 43 is particularly arranged so that there is no gap between the chip back surface 43 and the surface 82 of the insulating substrate 81. The edge 43a located on the short side (side with a length of 1.6 mm) is placed so as not to cause a gap with the surface 82. 2 corresponds to a predetermined edge of the present invention, and an edge 43a of the chip back surface 43 is opposed to the predetermined edge of the present invention. This corresponds to the edge located on the back surface of the chip.

  In the chip 40, for example, the corner area, the center area, and the peripheral areas of the edges 42a and 43a of the chip body 41 having a vertically long rectangular shape are set as active areas (also referred to as functional areas). Specifically, as shown in FIG. 3, the chip 40 has an MMI (Multi-Mode Interference) mixer 44 (also referred to as a 90 ° hybrid) and a waveguide type PD 45.

The MMI mixer 44 has a function of optically coupling the signal light and local light input into the chip 40 to separate them into an in-phase component and a quadrature phase component, and two SSCs for extracting the input signal. A (Spot-Size Converter) area 44a and one MMI area 44b for performing multimode interference, both of which are active areas.
However, as seen in FIG. 3, the SSC region 44a is formed in the corner region of the chip body 41 opposite to the edge 42a, and the MMI region 44b extends from the SSC region 44a toward the waveguide type PD45. The MMI mixer 44 has three wide inactive regions 44c that are gathered and formed in the central region of the chip body 41 where the waveguides merge. The inactive area 44c corresponds to a range excluding the active area of the present invention.

The waveguide type PD 45 has, for example, four PD / MIM (Metal-Insulator-Metal) regions 45a for receiving the output in, for example, four waveguides branched in the MMI region 44b at the end face. It is an active area.
However, as shown in FIG. 3, each PD / MIM region 45a is formed near both ends of the edge 42a or near the center of the edge 42a, and there are two inactive regions 45c in the waveguide type PD 45 forming the active region. .

  In this way, in the chip body 41, for example, three inactive areas 44c are formed over a wide range compared to the active areas of the SSC area 44a, the MMI area 44b, and the PD / MIM area 45a, for example. Therefore, in the optical module manufacturing apparatus, when the chip 40 is mounted on the insulating substrate 81, the collet adsorption range described later is limited to the inactive area 44c on the chip surface 42 only. Further, after the edge 43 a of the chip back surface 43 is brought into contact with the surface 82 of the insulating substrate 81, the entire chip back surface 43 is brought into contact with the surface 82.

(First embodiment)
4A and 4B are diagrams for explaining the first embodiment of the present invention. FIG. 4A is a front view of the collet, and FIG. 4B is a bottom view of the collet. 5A is a cross-sectional view taken along line AA in FIG. 4, and FIG. 5B is a cross-sectional view taken along line BB in FIG.
As shown in FIG. 4A, the collet 60 has a collet body 61, and a cylindrical pipe 63 is erected on the upper surface 62 of the collet body 61.

As shown in FIG. 5, a vent hole 64 is formed inside the collet body 61, and the vent hole 64 communicates with the pipe line 63. The inside of the pipe line 63 is connected to, for example, a vacuum pump (not shown), and when the air in the pipe line 63 is sucked by the vacuum pump, the inside of the vent hole 64 is depressurized to generate an adsorbing force on the collet 60. Can do.
On the lower surface 65 of the collet body 61, for example, three suction openings 66 communicating with the vent hole 64 are formed. Each suction opening 66 is provided at a position corresponding to the three inactive regions 44c of the MMI mixer 44 described in FIG.

A suction surface 67 is formed around the suction opening 66, and each suction surface 67 similarly abuts against the three inactive regions 44c.
Further, for example, two contact surfaces 68 are formed on the lower surface 65 of the collet body 61. The contact surface 68 is provided at a position corresponding to the two inactive regions 45c of the waveguide type PD 45 described with reference to FIG. 3, and contacts the two inactive regions 45c. It does not contact the edge 42a or the PD / MIM area 45a forming the active area.

Further, the mesh portion in FIG. 5 is a member that blocks the vent hole 64 when the collet 60 is manufactured, and no suction opening is formed in the vicinity of the contact surface 68 as shown in FIG. . Therefore, no attracting force is generated in the two inactive regions 45c in the waveguide type PD45.
As shown in FIG. 4A, when the height h from the lower surface 65 to the suction surface 67 and the height H from the lower surface 65 to the contact surface 68 are set, the latter height H is the former height h. For example, it is set to a value about 10 μm (1 μm = 1 × 10 ⁻⁶ m), and the contact surface 68 protrudes below the suction surface 67.

  As a result, when the thin chip 40 is mounted on the insulating substrate 81, when the collet 60 adsorbing the three inactive regions 44c of the MMI mixer 44 descends toward the insulating substrate 81, for example, first, the chip that is the active region The edge 43 a of the back surface 43 contacts the surface 82 of the insulating substrate 81. The peripheral region of the edge 43a is a range that is not attracted, but can be mounted on the surface 82 without a gap.

Subsequently, when the collet 60 further descends toward the insulating substrate 81, the entire chip back surface 43 comes into contact with the surface 82 of the insulating substrate 81. In this way, after the edge 43a is brought into contact with the front surface 82, the entire chip back surface 43 is brought into contact with the front surface 82, so that uniform mounting on the insulating substrate 81 in which warpage of the chip body 41 is prevented can be achieved.
Further, since the contact surface 68 of the collet 60 protrudes from the suction surface 67, the edge 43a of the chip back surface 43 can be easily brought into contact with the front surface 82.

(Second Embodiment)
FIG. 6 is a diagram for explaining a second embodiment of the present invention. In the first embodiment, the collet is devised, but a stage on which the insulating substrate is placed may be devised.
Specifically, as shown in FIG. 6, the stage 70 has a first support surface 71 and a second support surface 72. In FIG. 6, an exaggerated stage 70 is drawn to facilitate understanding of the second embodiment.

The first support surface 71 supports the back surface 83 of the insulating substrate 81 so that the front surface 82 of the insulating substrate 81 faces the peripheral region of the edge 43a of the chip back surface 43, and the second support surface 72 The back surface 83 is supported so as to face a region excluding the peripheral region of the edge 43a (for example, the three inactive regions 44c of the MMI mixer 44 described in FIG. 3).
Then, as shown in FIG. 6, when the angle θ between the upper surface of the stage 70 and the horizontal plane is used, the chip body 41 having a length of about 4.1 mm is used, and the protrusion of 10 μm is used as in the first embodiment. Assuming the amount, tan θ = 10 μm / 4.1 mm (θ = about 0.14), and the first support surface 71 protrudes above the second support surface 72.

  As a result, when the chip 40 is mounted on the insulating substrate 81, for example, when the collet 60 with the contact surface 68 and the suction surface 67 having the same height is lowered toward the insulating substrate 81, for example, first, the chip back surface that is the active region 43 is in contact with the surface 82 of the insulating substrate 81. The peripheral region of the edge 43a is a range that is not attracted, but can be mounted on the surface 82 without a gap.

If θ is set to about 0.3 at the maximum, uniform mounting on the insulating substrate 81 in which the warpage of the chip body 41 is prevented can be achieved without increasing the load on the peripheral region of the edge 43a.
In the second embodiment, the collet 60 having the contact surface 68 and the suction surface 67 having the same height has been described as an example. However, the collet 60 described in the first embodiment may be used.

DESCRIPTION OF SYMBOLS 1 ... Optical module, 2 ... Package, 2a ... Base, 3 ... Output terminal, 4 ... Single mode fiber, 5,11 ... Ferrule, 6, 12, 13 ... Sleeve, 7 ... Joint sleeve, 8, 14 ... Lens holder, 9, 26, 29, 33, 36 ... Condensing lens, 10 ... Polarization maintaining fiber, 15, 21 ... Collimating lens, 20 ... VOA, 22, 31 ... Beam splitter, 23 ... PD for power monitor, 24 ... Polarization Beam splitter, 25, 32 ... Skew adjusting element, 28, 35 ... Mirror, 30 ... Polarizer, 34 ... Half wave plate, 40 ... Chip, 41 ... Chip body, 42 ... Chip surface, 42a, 43a ... Edge, 43 ... Chip back surface, 44 ... MMI mixer, 44a ... SSC region, 44b ... MMI region, 44c, 45c ... inactive region, 45 ... waveguide type PD, 45a PD / MIM area, 50 ... Amplifier, 60 ... Collet, 61 ... Collet body, 62 ... Upper surface, 63 ... Pipe, 64 ... Vent, 65 ... Lower surface, 66 ... Suction opening, 67 ... Suction surface, 68 ... Contact surface, 70 ... stage, 71 ... first support surface, 72 ... second support surface, 81 ... insulating substrate, 82 ... front surface, 83 ... back surface.

Claims (4)

An active module for realizing a predetermined function is a method for manufacturing an optical module in which a chip provided at least in a peripheral region of a predetermined edge of a chip surface is mounted on an insulating substrate,
Adsorbing the area excluding the active area of the chip surface;
Contacting an edge located on the back surface of the chip facing the predetermined edge with the surface of the insulating substrate;
And a step of bringing the entire back surface of the chip into contact with the surface of the insulating substrate. An optical module manufacturing apparatus for mounting a chip provided with an active region for realizing a predetermined function at least in a peripheral region of a predetermined edge of a chip surface on an insulating substrate,
A collet that adsorbs a range excluding the active area of the chip surface, and a stage on which the insulating substrate is placed,
An optical module manufacturing apparatus, wherein an edge located on a back surface of a chip facing the predetermined edge is brought into contact with the surface of the insulating substrate, and then the entire back surface of the chip is brought into contact with the surface of the insulating substrate. The collet has a suction surface that is formed around the suction opening and contacts a range excluding the active region, and a contact surface that contacts a peripheral region of the predetermined edge,
The optical module manufacturing apparatus according to claim 2, wherein the contact surface protrudes from the suction surface. The stage includes a first support surface that supports a back surface of the insulating substrate such that a surface of the insulating substrate faces a peripheral region of the edge located on the chip back surface, and the surface of the insulating substrate is the chip back surface. A second support surface that supports the back surface of the insulating substrate so as to face the range excluding the peripheral region of the edge located at
4. The optical module manufacturing apparatus according to claim 2, wherein the first support surface protrudes from the second support surface. 5.

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