Encapsulation of optoelectronic components

• US 5,818,990 A
• Filed: 01/29/1997
• Issued: 10/06/1998
• Est. Priority Date: 03/18/1994
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Moll, Hans, Tinghag, Pia, Janson, Mats, Engstrand, Jan .ANG.ke, Palmskog, Goran, Eriksen, Paul, Steijer, Odd
• Primary Examiner(s): NGO, HUNG NHAT
• Application Number:
  US08/722,119
• Time in Patent Office: 615 Days
• Field of Search: 385/88-94, 385/14, 385/49, 385/83, 385/65
• US Class Current: 385/49
• CPC Class Codes: G02B 6/4201 Packages, e.g. shape, construction, internal or external details
• CPC Class Codes: G02B 6/4253 by embedding housing components in an adhesive or a polymer material G02B6/4212 takes precedence
• CPC Class Codes: G02B 6/4255 Moulded or casted packages
• CPC Class Codes: G02B 6/4257 having a supporting carrier or a mounting substrate or a mounting plate G02B6/3648 takes precedence

Abstract

An encapsulated optocomponent (1) comprises a single-crystal silicon wafer (3) and waveguides (9) located thereon, which at least partly are manufactured by means of process methods taken from the methods for manufacturing electronic integrated circuits. The waveguides (9) extend from an edge of the optoelectronic component (1) to an optoelectronic, active or passive component (11) attached to the surface of the silicon wafer (3). Over the region for connecting the waveguides (9) to the optoelectronic component (11) a transparent plastics material is molded (17), for instance an elastomer, having a refractive index adjusted to improve the optical coupling between the waveguides (9) and the optoelectronic component (11). The molding (17) covers advantageously all of said component (11) to also reduce thermal stresses between it and an exterior, protective layer (19) of a curable plastics material. The molded layer (17) can also cover the whole area of the waveguides (9) to form an upper cladding thereof. Guide grooves (5) are arranged in the silicon wafer (3) for positioning guide pins (7), utilized in the connection of the optocomponent (1) to another optocomponent having guides for guide pins and waveguides configured in the same way.

Claims

1. A method for the manufacture of an optocomponent, comprising the steps of:

producing a plate of an inorganic material,

producing at least portions of waveguides at a surface of the plate,

mounting an optoelectronic component on said surface of the plate for an optical coupling to the waveguides and for connection to electrical terminals,

coating at least a portion of the surface of the plate including at least a portion of a free surface of the waveguide portions and a free surface of the optoelectronic component with a first plastics material,

applying on top of at least an area of the plate covered with the first plastics material a layer of a second plastics material

wherein the second plastics material has a high mechanical resistance to form a protection of the optoelectronic component and the waveguides and

the first plastics material has a high elasticity to relieve mechanical stresses resulting from temperature changes.

2. A method according to claim 1, wherein

the first plastics material is also coated over a region at one end of the waveguides where the waveguides are coupled to the optoelectronic component, and

the first plastics material is a transparent material having a refracting index to enhance the optical coupling between the component and the waveguide.

3. A method according to claim 1, wherein

the first plastics material is first coated on top of waveguide portions and

the first plastics material is a transparent material having an adapted refractive index to form an upper cladding portion of the waveguides.

4. A method for the manufacture of an optocomponent, comprising the steps of:

producing a plate of an inorganic material,

producing at least one cladding and at least one core associated said cladding at a surface of the plate for obtaining at least one waveguide, and

mounting an optoelectronic component on said surface of the plate for optical coupling to the waveguides and for connection to electrical terminals,

wherein a lower part of said at least one cladding and said at least one core are first produced by process technological methods at a top of a surface of the plate,

an upper portion of the at least one cladding is produced by covering at least a portion of the surface of the plate including at least a portion of a free surface of the at least one lower cladding and at least a portion of a free surface of the at least one core with a plastics material, and

wherein at least said surface of the plate including free surfaces of the cladding and the plastics material is coated with an additional plastics layer.

5. A method according to claim 4, wherein for producing at least one waveguide a lower portion of cladding is first produced by coating at least one layer by process technological methods over a selected region on a surface of the plate, as at least one elongated and strip shaped region and subsequently producing at least one core by process technological methods by coating an additional layer having an elongated shape at a surface of the at least one layer which forms the lower portion of the at least one cladding.

6. A method according to claim 4, wherein at least a connection region between the component and at least one waveguide is coated with a plastics material.

7. A method according to claim 6, wherein the plastics material is a transparent material having a refractive index for enhancing the optical coupling between the component and the at least one waveguide.

8. A method for the manufacture of an optocomponent comprising an optical connector means, comprising the steps of:

producing a plate of an inorganic material,

producing at least one waveguide at a surface of the plate,

mounting an optoelectronic component on the surface of the plate for an optical coupling to the waveguides,

producing accurately aligned guide grooves in the surface of the plate,

coating at least a connection region between the component and at least one waveguide by molding thereon a transparent material having a selected refractive index to enhance the optical coupling between the component and the at least one waveguide, and

molding on top of at least an area of the plate where the transparent material is coated a protective plastics layer.

9. A method according to claim 8, wherein a plate of single-crystal silicon is produced and wherein the guide grooves are formed by etching.

10. A method according to claim 8, wherein a plate of single-crystal silicon is produced and wherein at least one waveguide at least partly is produced by process technological methods.

11. A method according to claim 8, wherein at least one of the step of producing the guide grooves and the the step of producing the at least one waveguide includes producing at least one projection on the plate surface for an accurate positioning of the optoelectronic component.

12. A method according to claim 11, wherein a plate of single-crystal silicon is produced and wherein the at least one projection is produced by process technological methods.

13. A method according to claim 8, further comprising the step of disposing alignment devices in the guide grooves for connecting optical contact means to corresponding optical contact means having at least partly the same shape in the guide grooves before the step of molding the plastics layer.

14. A method according to claim 8, wherein at least one waveguide is produced by placing an optical fiber in a guide groove.

15. An encapsulated optocomponent, comprising:

a substrate of an inorganic material,

an optoelectronic component mounted to a surface of the substrate optical coupling between the waveguides and for connection to electrical terminals,

waveguides at least partly formed in and/or on the surface of the substrate, wherein the optoelectric component is optically coupled to the waveguides,

a first plastics layer of an elastomer material covering at least a portion of the surface of the substrate including at least a portion of a free surface of the waveguides and a free surface of the optoelectronic component and

a second plastics layer covering at least all of the first plastics layer on the surface of the substrate,

wherein the material of the second plastics material has a high mechanical resistance to form a protection of the optoelectronic component and the waveguides and

the material of the first plastics material is soft and has a high elasticity to relieve mechanical stresses resulting from temperature changes.

16. A method for the manufacture of an optocomponent, comprising the steps of:

producing a plate of an inorganic material,

producing at least one cladding and at least one core associated said cladding at a surface of the plate for obtaining at least one waveguide, and

mounting an optoelectronic component on said surface of the plate for optical coupling to the waveguides and for connection to electrical terminals,

wherein a lower part of said at least one cladding and said at least one core are first produced by process technological methods at a top of a surface of the plate,

wherein an upper portion of the at least one cladding is produced by covering at least a portion of the surface of the plate including at least a portion of a free surface of the at least one lower cladding and at least a portion of a free surface of the at least one core with a plastics material,

wherein at least a connection region between the component and at least one waveguide is coated with a plastics material, and

wherein the plastics material is a transparent material having a refractive index for enhancing the optical coupling between the component and the at least one waveguide.

17. A method according to claim 16, wherein for producing at least one waveguide a lower portion of cladding is first produced by coating at least one layer by process technological methods over a selected region on a surface of the plate, as at least one elongated and strip shaped region and subsequently producing at least one core by process technological methods by coating an additional layer having an elongated shape at a surface of the at least one layer which forms the lower portion of the at least one cladding.

18. A method according to claim 16, further comprising the step of coating at least said surface of the plate including free surfaces of the cladding and the plastics material with an additional plastics layer.