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US6356686B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Optoelectronic device encapsulant

Assignee: International Business Machines Corp
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Filing: 1999-09-03
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Granted: 2002-03-12
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Expires: 2019-09-03
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Abstract

Abstract An optically clear encapsulant for optoelectronic packages exhibits a suitably high viscosity both to replace a silicon nitride passivation layer required on a VCSEL die and to fill a gap between the die and an optical coupler, preventing light signal degradation. The encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers (nm) with substantially no Mie scattering since particulate fillers are not required to modulate viscosity in the encapsulant. Also, the encapsulant further seals wire bonds between the die and a cable header to prevent abrasive wear. The gap-filling encapsulant is particularly suitable for use with vertical cavity surface emitting laser (VCSEL) technology. The encapsulant includes prior to curing, a difunctional acrylate epoxy resin exhibiting pseudoplastic flow and a viscosity of greater than about 0.7×10 6 centipoise. Accordingly, a method of manufacturing an optical subassembly may eliminate a separate passivation step and instead fill the gap between the die and optical coupler with an optically clear encapsulant.

Inventors

  • 👤 Joseph Paul Kuczynski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 19:35
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4204; G02B6/421; G02B6/4212; G02B6/4292

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 147 words
An optoelectronic package comprising: a) a substrate having an array of one or more sources or detectors, the sources or detectors adapted, respectively, to generate or receive a light signal; b) an optical coupler aligned with the array such that a gap is formed between the optical coupler and the array of one or more sources or detectors, wherein the light signal passes through the gap between optical coupler and the array of one or more sources or detectors during operation; and c) an optically transparent substrate encapsulant in contact with the substrate that substantially fills the gap between optical coupler and the array of one or more sources, wherein the encapsulant both passivates the sources or detectors and prevents interfering accumulations of matter from forming in the gap without degradation of the light signal, wherein the optically transparent comprises difunctional acrylated epoxy resin prior to curing.
Claim 2
Dependent Claim 147 words
An optoelectronic package comprising: a) a substrate having an array of one or more sources or detectors, the sources or detectors adapted, respectively, to generate or receive a light signal; b) an optical coupler aligned with the array such that a gap is formed between the optical coupler and the array of one or more sources or detectors, wherein the light signal passes through the gap between optical coupler and the array of one or more sources or detectors during operation; and c) an optically transparent substrate encapsulant in contact with the substrate that substantially fills the gap between optical coupler and the array of one or more sources, wherein the encapsulant both passivates the sources or detectors and prevents interfering accumulations of matter from forming in the gap without degradation of the light signal, wherein the optically transparent comprises difunctional acrylated epoxy resin prior to curing.
Claim 3
Dependent Claim 26 words
The device of claim 1 , wherein the encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering.
Claim 4
Dependent Claim 15 words
The device of claim 1 , wherein the sources comprise vertical cavity surface emitting lasers.
Claim 5
Dependent Claim 15 words
The device of claim 1 , wherein the gap is greater than about 50 micrometers.
Claim 6
Dependent Claim 13 words
The device of claim 4 , wherein the gap is about 100 micrometers.
Claim 7
Dependent Claim 28 words
The device of claim 1 , further comprising wire bonds from the substrate to a cable header, wherein the encapsulant further seals the wire bonds from abrasive wear.
Claim 8
Dependent Claim 57 words
An encapsulant for an optoelectronic source comprising, prior to curing, a functionalized resin and an effective amount of a curing initiator, wherein the functionalized resin comprises difunctional acrylated epoxy resin, wherein, after curing, the encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering and passivates the optoelectronic source.
Claim 9
Dependent Claim 57 words
An encapsulant for an optoelectronic source comprising, prior to curing, a functionalized resin and an effective amount of a curing initiator, wherein the functionalized resin comprises difunctional acrylated epoxy resin, wherein, after curing, the encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering and passivates the optoelectronic source.
Claim 10
Dependent Claim 15 words
The encapsulant of claim 7 , wherein the encapsulant exhibits psuedoplastic flow prior to curing.
Claim 11
Dependent Claim 23 words
The encapsulant of claim 7 , wherein the functionalized resin exhibits a viscosity of greater than about 0.7×10 6 centipoise prior to curing.
Claim 12
Dependent Claim 14 words
The encapsulant of claim 9 , wherein the viscosity comprises about 1.2×10 6 centipoise.
Claim 13
Dependent Claim 13 words
The encapsulant of claim 7 , wherein the initiator comprises a photo initiator.
Claim 14
Dependent Claim 47 words
The encapsulant of claim 7 , wherein, after curing, the encapsulant exhibits thermal stability up to about 215° C., adheres to gold or other metal layers suitable for tape automated bonding, and exhibits a moisture permeation rate of less than about 7 (gram×milliinches)/(24 hours×100 inches 2 ).
Claim 15
Independent Claim 157 words
A method of manufacturing an optical subassembly comprising the steps of: affixing a non-passivated die to a die carrier, the die having an array of one or more sources or detectors, the sources or detectors adapted, respectively, to generate or receive a light signal; aligning an optical coupler with the array such that a gap is formed between the optical coupler and the array of one or more sources or detectors, wherein the light signal passes through the gap between optical coupler and the array of one or more sources or detectors during operation; dispensing an encapsulant on at least the array, wherein the encapsulant substantially fills the gap between the optical coupler and the array of one or more sources and prevents interfering accumulations of matter from forming in the gap, wherein the encapsulant comprises difunctional acrylated epoxy resin; and curing the encapsulant, wherein the cured encapsulant exhibits optical transparency and passivates the sources or detectors.
Claim 16
Independent Claim 157 words
A method of manufacturing an optical subassembly comprising the steps of: affixing a non-passivated die to a die carrier, the die having an array of one or more sources or detectors, the sources or detectors adapted, respectively, to generate or receive a light signal; aligning an optical coupler with the array such that a gap is formed between the optical coupler and the array of one or more sources or detectors, wherein the light signal passes through the gap between optical coupler and the array of one or more sources or detectors during operation; dispensing an encapsulant on at least the array, wherein the encapsulant substantially fills the gap between the optical coupler and the array of one or more sources and prevents interfering accumulations of matter from forming in the gap, wherein the encapsulant comprises difunctional acrylated epoxy resin; and curing the encapsulant, wherein the cured encapsulant exhibits optical transparency and passivates the sources or detectors.
Claim 17
Dependent Claim 27 words
The method of claim 13 , wherein the cured encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering.
Claim 18
Dependent Claim 34 words
The method of claim 13 , wherein, prior to curing, the encapsulant comprises a functionalized resin, exhibiting a viscosity of greater than about 0.7×10 6 centipoise, and an effective amount of a curing initiator.
Claim 19
Dependent Claim 18 words
The method of claim 13 , wherein the step of curing comprises exposing the encapsulant to ultraviolet radiation.
Claim 20
Dependent Claim 37 words
The method of claim 13 , wherein the step of dispensing comprises further dispensing the encapsulant on wire bonds from the die to a cable header, wherein the encapsulant further seals the wire bonds from abrasive wear.
Claim 21
Dependent Claim 15 words
The method of claim 13 , wherein the gap is greater than about 50 micrometers.
Claim 22
Dependent Claim 124 words
An optoelectronic package comprising: a) a die having an array of one or more vertical cavity surface emitting lasers; b) an optical coupler aligned with the array, wherein a gap is formed between the die and the optical coupler and wherein laser signals pass through the gap during operation; c) an optically transparent substrate encapsulant in contact with the die, the encapsulant exhibiting substantially no Mie scattering and substantially filling the gap between the die and optical coupler, wherein the optically transparent substrate encapsulant comprises difunctional acrylated epoxy resin prior to curing; and d) wire bonds from the die to a cable header, wherein the encapsulant both seals the lasers and wire bonds and prevents interfering accumulations of matter from forming in the gap.
Claim 23
Dependent Claim 124 words
An optoelectronic package comprising: a) a die having an array of one or more vertical cavity surface emitting lasers; b) an optical coupler aligned with the array, wherein a gap is formed between the die and the optical coupler and wherein laser signals pass through the gap during operation; c) an optically transparent substrate encapsulant in contact with the die, the encapsulant exhibiting substantially no Mie scattering and substantially filling the gap between the die and optical coupler, wherein the optically transparent substrate encapsulant comprises difunctional acrylated epoxy resin prior to curing; and d) wire bonds from the die to a cable header, wherein the encapsulant both seals the lasers and wire bonds and prevents interfering accumulations of matter from forming in the gap.
Claim 24
Dependent Claim 77 words
An encapsulant for an optoelectronic source consisting essentially of, prior to curing, a difunctional acrylated epoxy resin and an effective amount of a curing photo initiator, wherein, prior to curing, the functionalized resin exhibits a viscosity of greater than about 0.7×10 6 centipoise and the encapsulant exhibits pseudoplastic flow and wherein, after curing, the encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering and passivates the optoelectronic source.
Claim 25
Dependent Claim 77 words
An encapsulant for an optoelectronic source consisting essentially of, prior to curing, a difunctional acrylated epoxy resin and an effective amount of a curing photo initiator, wherein, prior to curing, the functionalized resin exhibits a viscosity of greater than about 0.7×10 6 centipoise and the encapsulant exhibits pseudoplastic flow and wherein, after curing, the encapsulant exhibits optical transparency to light having a wavelength of about 850 nanometers with substantially no Mie scattering and passivates the optoelectronic source.
Claim 26
Independent Claim 138 words
A method of manufacturing an optical subassembly comprising the steps of: affixing a non-passivated die to a die carrier, the die having an array of one or more vertical cavity surface emitting lasers; forming wire bonds from the die to a cable header; dispensing an encapsulant at least on the array and wire bonds, wherein the encapsulant comprises difunctional acrylated epoxy resin; aligning an optical coupler with the array, wherein a gap is formed between the die and the optical coupler and wherein laser signals pass through the gap during operation; curing the encapsulant by exposure to ultraviolet radiation, wherein the cured encapsulant exhibits optical transparency with substantially no Mie scattering, seals the lasers and wire bonds, substantially fills the gap between the die and optical coupler, and prevents interfering accumulations of matter from forming in the gap.
Claim 27
Independent Claim 138 words
A method of manufacturing an optical subassembly comprising the steps of: affixing a non-passivated die to a die carrier, the die having an array of one or more vertical cavity surface emitting lasers; forming wire bonds from the die to a cable header; dispensing an encapsulant at least on the array and wire bonds, wherein the encapsulant comprises difunctional acrylated epoxy resin; aligning an optical coupler with the array, wherein a gap is formed between the die and the optical coupler and wherein laser signals pass through the gap during operation; curing the encapsulant by exposure to ultraviolet radiation, wherein the cured encapsulant exhibits optical transparency with substantially no Mie scattering, seals the lasers and wire bonds, substantially fills the gap between the die and optical coupler, and prevents interfering accumulations of matter from forming in the gap.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2005-03-11 2005-09-10 2006-03-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2009-03-11 2009-09-10 2010-03-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2013-03-11 2013-09-10 2014-03-12 $7700.00 Window Closed / Lapsed

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