Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F77/00—Constructional details of devices covered by this subclass
  • H10F77/50—Encapsulations or containers
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
  • G02B6/422—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements
  • G02B6/4226—Positioning means for moving the elements into alignment, e.g. alignment screws, deformation of the mount
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F77/00—Constructional details of devices covered by this subclass
  • H10F77/40—Optical elements or arrangements
  • H10F77/407—Optical elements or arrangements indirectly associated with the devices
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
  • G02B6/4236—Fixing or mounting methods of the aligned elements
  • G02B6/4237—Welding
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
  • G02B6/4236—Fixing or mounting methods of the aligned elements
  • G02B6/4238—Soldering
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4248—Feed-through connections for the hermetical passage of fibres through a package wall
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/4805—Shape
  • H01L2224/4809—Loop shape
  • H01L2224/48091—Arched
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/30—Technical effects
  • H01L2924/301—Electrical effects
  • H01L2924/30107—Inductance
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/30—Technical effects
  • H01L2924/301—Electrical effects
  • H01L2924/3011—Impedance

Definitions

• the present invention relates generally to optoelectronic assemblies
• the present invention relates to an assembly having optical
• Optoelectronic packages provide submicron alignment
• the package includes a cover with a window
• optoelectronic device such as, for example, a laser
• Kluitmans et al. discuss a package for a laser diode coupled to an
• the package includes a conducting rod so that the laser may be used at high speed.
• Shigeno describes a heat sink for cooling an enclosed laser
• the laser diode is preferably coupled to an optical fiber.
• optoelectronic package includes a substrate having a floor, a first optical element coupled to the substrate, a second optical element, and a flexure
• Figure 1 shows one embodiment of an optoelectronic package assembly.
• Figure 2A shows a side sectional view of the frame assembly of Figure 1
• Figure 2B shows the frame assembly of Figure 2A after planarization of
• Figure 2C shows how two optical components are positioned by pick
• Figure 2D shows the resulting optical alignment of the element in the
• Figure 3A shows a perspective view of the assembly before alignment of
• Figure 3B shows a side view of the assembly before alignment of the
• Figure 3C shows a top view of the assembly before alignment of the
• Figure 4A shows a perspective view of the assembly with the flexure
• Figure 4B shows a side view of the assembly after alignment and final
• Figure 4C shows a top view of the assembly after alignment and attach
• Figure 5A illustrates one embodiment of a 4 legged flexure.
• Figure 5B shows the fine alignment step using the back legs of a 4
• Figure 6 shows an alternate embodiment with a spring leaf attachment
• Figure 7 shows a side sectional view of a third embodiment of the
• the package comprises a substrate
• the substrate and its positioning floor are
• one or more raised platforms are also present.
• the raised platforms may be submounts
• the raised platforms may be attached, for example,
• soldering or brazing may even be part of the substrate material itself.
• edge emitting, side mounted, or waveguide In one embodiment, edge emitting, side mounted, or waveguide
• Micro-optical elements such as, for example, micro-
• lenses, filters, splitters, isolators are mounted directly on the package floor.
• the height of the platform and the height of the platform are the same.
• optical elements are chosen such that the edge emitting devices and the optical
• edge emitting devices may serve up to three purposes at a time: (i) providing
• the height of the platforms and frame is kept at a
• the assembly is essentially two dimensional and can be manufactured using pick
• the substrate, frame and platform assembly enables placement of the substrate, frame and platform assembly
• the height alignment between components is automatically set by the
• such components are mounted using a miniature flexure which allows for a small
• the flexure is made of thin
• the legs are joined by a bridge that supports
• the flexure may be designed so that in its natural (non-flexed) state, the optical axis of the optical component attached to the bridge rests slightly above
• Dragging the flexure in the plane parallel to the plane of the substrate may be preferred to correct the lateral position.
• the legs are permanently attached to the frame or substrate.
• the flexure has more than two legs.
• the first pair of legs is attached to the frame after coarse optical alignment.
• optical package is then
• Embodiments of the optoelectronic package described herein provide a much simpler and cost effective solution for hermeticity, without the need for
• hermeticity is obtained by using a top-hat
• connections with the exterior of the enclosure are provided by filled vias
• hermetic enclosure is facilitated by a set of electrical connections printed
• top and bottom of the substrate are directly on the top and bottom of the substrate as a set of patterns.
• the package, or to a ball grid array or similar structure, underneath the package can be accomplished without any additional wiring nor expensive through-
• thickness of the substrate material which in one embodiment is on the order of
• the quasi-planar substrate with raised platforms in conjunction with the flexure, simultaneously provides a high-precision optical alignment bench
• At least one embodiment of the present invention provides a
• Such a package may be manufactured
• Figure 1 shows one embodiment of an optoelectronic assembly, package
• Assembly comprises a substrate 12 with a positioning floor 14.
• positioning floor 14 is substantially
• planar, and substrate 12 comprises an electrically isolating material with a low
• coefficient of thermal expansion such as alumina or beryllium oxide.
• raised platform 20 is created by a submount attached to
• Optical elements, or components, are mounted on positioning floor 14
• a lens 16 is mounted on substrate 12, and
• an edge emitting optoelectronic element 18 such as, for example, a laser diode
• An optical element 22 is attached to on flexure 24, by, for example,
• flexure 24 comprises two
• element 22 is a single mode
• optical fiber but it may be any element that requires optical alignment with
• a frame 32 may be attached to substrate 12. The ends of legs 26 and 27
• frame 32 has a protruding
• a cap 38 is attached to frame 32, creating an airtight seal.
• cap 38 has a top hat shape and an peripheral lip 40 that can be
• the hermetic seal may be created by a process such as seam
• optical element 16 is preferably less than 1/5 of that length.
• thickness of frame 30 and platform 20 is 0.250 millimeters, height
• lens 16 is 0.5 millimeter, and length of substrate 12 is about 10 millimeters.
• wire bond 42 connects active optical element 18 to
• electrically conductive pattern 44 which is on the top side of positioning floor
• Filled conductive via 46 hermetically connects pattern 44 to electrically
• bottom side of positioning floor 14 are also provided for connections to
• signals can be distributed to ball grid
• package 10 is realized without frame 32, and the
• flexure 26 is attached directly to floor 14,
• two concentric frames are used, where an outer one on attaching cap 38 and an inner one for attaching flexure 24.
• FIG. 1 An axis A bisects package 10, as shown in Figure 1.
• Figure 2A is a cross- 1 sectional view of assembly 10, taken along axis A. Since vertical alignment of
• the optical element mounted thereon is reduced to the correct height.
• Fig 2A shows substrate 12 with frame 24 and platform 20 before
• optical element 16 slightly more than that of the optical axis of optical element 16 shown for
• Figure 2B shows frame 24 and platform 20, including optical element 15, after precision polishing, so that frame 32 and platform 20 have a
• element 18 is a laser diode, whose emitted light is
• element 16 which is a lens
• element 22 which is an optical fiber.
• the alignment of laser, lens, and fiber is
• Optical plane P is a distance h from floor 16.
• the lens has an optical axis OA a distance from the bottom surface of the lens.
• Platform 20 has height h,
• platform height control may be used, including, but not limited to, electro ⁇
• Figs. 4A, 4B, 4C, 5A and 5B describe a flexure alignment device
• flexure 24 comprises a bridge 30 and
• bridge 30 The extremities of legs 26 and 27 rest on frame 32. In an alternative design, the extremities of the legs rest directly onto substrate 12.
• Bridge 30 holds an optical element 22. In one embodiment, the optical element 22
• flexure 24 is preferably made
• flexure 24 is about 170 microns thick, and spring regions 28 and 29 are approximately 85 microns thick. It will be clear from the following how legs 26 and 27, bridge 30
• the process begins by first attaching optical element 22 to bridge 30 of
• flexure 24 by a process such as, for instance, soldering or adhesive bonding.
• flexure 24 simply rests on frame 32 (or on substrate 12, in a ring-less
• At least one first optical image with no further attachment method.
• At least one first optical image with no further attachment method.
• element 16 is already attached to optical assembly 10 and defines an optical
• a laser diode 18 and a lens 16 are
• flexure 24 is designed such that optical axis BC is higher than optical axis OA, as shown in the side view of assembly 10 on Figure 3B.
• BC is about 100 to 200 microns higher than OA when no pressure
• the axis OA and BC may also be offset from each other in the horizontal plane
• Removable alignment tool 52 is used to apply pressure to the top of
• Tool 52 also features pins 55 and 54 with conical ends 56 and 57
• a vacuum tool can also be used.
• tool 52 is lowered onto bridge 30.
• Tool 52 is also moved
• alignment is monitored by measuring coupled power at the
• leg extremities are attached to the ring frame 32 or substrate 12.
• One attachment process is laser
• micro welding through laser beam 62, which creates welding spots 60 and 61.
• Welding spots permanently attach metallic legs 26 to metallic ring frame 32.
• attachment processes may also be used, such as UV curable adhesives or
• tool 52 is raised from
• Figure 5A shows one flexure
• 5A comprises two pairs of legs, a front pair of legs 26 and 27 and a rear pair of
• the front pair of legs is located close to optical element 16 as
• Front legs 26 and 27 are permanently attached to frame 32 as previously described, using for example laser welding spots 60 and 61. Post-attachment shift is corrected in a second
• Alignment tool 52 is
• Figure 6 shows variations and further improvements of the package embodiment.
• optical element 16 is pressed
• leaf 81 is attached to frame 32 by laser welding for example.
• spring leaf 81 has the advantage of not necessitating an adhesive or solder layer
• the package embodiment of Figure 6 comprises an optical element 82
• the package embodiment of Figure 6 further comprises an electronic
• component 84 such as an impedance matching resistor, mounted onto floor 14
• thermistors such as, for example, thermistors, chokes, integrated circuits can be mounted
• the package of Figure 6 also contains peripheral contact pads 88 on the top surface of substrate 12. Contact pads 88 are connected to inside electrical
• Figure 7 shows another embodiment of the optical package.
• fiber 92 comprises a distributed Bragg reflection (DBR) grating 90 held in place by flexure 94.
• Laser 93 emits light into fiber 92.
• laser 93 has an antireflection coated or angled front facet to prevent reflection of the light by the facet into the laser waveguide.
• Grating 90 strongly reflects a predetermined wavelength back into laser 93.
• a well-known adhesive or bonding technique may be used to mount the elements and /or the raised platforms supporting such elements.
• a laser system is thereby created, having a laser cavity that comprises grating 90 as well as the cavity of laser 93.
• the laser system of Figure 7 has a resonant wavelength equal to the predetermined wavelength that corresponds to grating 90.
• the advantage of this embodiment is the superior mechanical stability of the fiber position with respect to the laser facet, which prevents the occurrence of mode hops, and lowers assembly cost.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Optical Couplings Of Light Guides (AREA)
• Semiconductor Lasers (AREA)
• Led Device Packages (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22861055

Family Applications (1)

Country Status (8)

Cited By (4)

Families Citing this family (68)

Citations (4)

Family Cites Families (33)

• 1999
  • 1999-01-11 US US09/229,395 patent/US6207950B1/en not_active Expired - Lifetime
• 2000
  • 2000-01-06 DE DE60041811T patent/DE60041811D1/de not_active Expired - Fee Related
  • 2000-01-06 HK HK02103417.7A patent/HK1042376B/en not_active IP Right Cessation
  • 2000-01-06 AU AU27225/00A patent/AU2722500A/en not_active Abandoned
  • 2000-01-06 CA CA2360372A patent/CA2360372C/en not_active Expired - Fee Related
  • 2000-01-06 EP EP00905568A patent/EP1151454B1/en not_active Expired - Lifetime
  • 2000-01-06 JP JP2000594131A patent/JP4290893B2/ja not_active Expired - Fee Related
  • 2000-01-06 WO PCT/US2000/000416 patent/WO2000042629A1/en not_active Ceased
• 2001
  • 2001-03-19 US US09/812,267 patent/US6586726B2/en not_active Expired - Lifetime

Patent Citations (4)

Non-Patent Citations (1)

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