Method of manufacturing an optically coupled device
An optically coupled device includes a light emitting element and a light receiving element which are electrically isolated from each other, and an optical waveguide allowing therethrough transmission of light from the light emitting element to the light receiving element, wherein the optical waveguide is covered with an encapsulation resin containing a light reflective inorganic particle which is typically composed of titanium oxide, the light emitting element and the light receiving element are respectively provided on a base (for example, package terminals), and the entire portion of the outer surface of the optical waveguide, brought into contact with none of the light emitting element, the light receiving element and the base, is covered with the encapsulation resin.
1. A method of manufacturing an optically coupled device comprising:
a first step providing an optical waveguide allowing therethrough transmission of light from a light emitting element to a light receiving element which are electrically isolated from each other, said optical waveguide extending from said light emitting element to said light receiving element, and said optical waveguide optically directly connecting said light emitting element and said light receiving element, and
a second step covering said optical waveguide with a resin containing a light reflective inorganic particle,
the steps being carried out in this order.
2. The method of manufacturing an optically coupled device according to claim 1 , wherein said second step further comprises:
a step of curing said resin.
3. The method of manufacturing an optically coupled device according to claim 1 , wherein the resin contains 15-25% by weight of the reflective inorganic particle.
4. The method of manufacturing an optically coupled device according to claim 1 , wherein the reflective inorganic particle has a particle size of 25-35 nm.
5. The method of manufacturing an optically coupled device according to claim 1 , wherein the resin is a thermosetting epoxy resin.
6. The method of manufacturing an optically coupled device according to claim 1 , wherein the resin contains 50-60% by weight of silica.
7. The method of manufacturing an optically coupled device according to claim 1 , wherein said light reflective inorganic particle is a particle of at least any one species of inorganic material selected from titanium oxide, aluminum oxide, mica, aluminum nitride, and boron nitride.
8. A method of manufacturing an optically coupled device comprising:
providing an optical waveguide allowing therethrough transmission of light from a light emitting element to a light receiving element which are electrically isolated from each other,
, wherein
said optical waveguide comprising a body formed into a flat plate geometry; a first bonding portion which connects said body and said light emitting element with each other; and a second bonding portion connecting said body and said light receiving element; said body being provided so as to extend from said light emitting element to said light receiving element, while placing said first and second bonding portions respectively in between, and said first bonding portion allowing therethrough transmission of light from said light emitting element to said body, said body allowing therethrough transmission of light from said first bonding portion to said second bonding portion, and said second bonding portion allowing therethrough transmission of light from said body to said light receiving element, in sequence,
the surface of said light emitting element opposed to said body, and the surface of said light receiving element opposed to said body being differently distant from said body,
wherein said first step further comprises:
a step of dropping a light-transmissive resin, which respectively composes said first and second bonding portions, onto said light emitting element and said light receiving element, while setting the amount of dropping and the range of dropping, so as to make the surface of said first bonding portion opposed to said body and the surface of said second bonding portion opposed to said body aligned at the same level,
a step of providing said body so as to extend from said light-transmissive resin composing said first bonding portion to said light-transmissive resin composing said second bonding portion, and a step of curing said light-transmissive resin composing said first bonding portion, and said light-transmissive resin composing said second bonding portion,
the steps being carried out in this order.
9. The method of manufacturing an optically coupled device according to claim 8 ,
wherein in said step of dropping said light-transmissive resin onto said light emitting element and said light receiving element, said light-transmissive resin is dropped while setting the amount of dropping and the range of dropping, so as to make said first bonding portion and said second bonding portion spaced from each other, and so as to allow said resin containing said light reflective inorganic particle to reside between said first bonding portion and said second bonding portion.
10. The method of manufacturing an optically coupled device according to claim 8 , wherein the resin contains 15-25% by weight of the reflective inorganic particle.
11. The method of manufacturing an optically coupled device according to claim 8 , wherein the reflective inorganic particle has a particle size of 25-35 nm.
12. The method of manufacturing an optically coupled device according to claim 8 , wherein the resin is a thermosetting epoxy resin.
13. The method of manufacturing an optically coupled device according to claim 8 , wherein the resin contains 50-60% by weight of silica.
14. The method of manufacturing an optically coupled device according to claim 8 , wherein said light reflective inorganic particle is a particle of at least any one species of inorganic material selected from titanium oxide, aluminum oxide, mica, aluminum nitride, and boron nitride.
15. A method of manufacturing an optically coupled device comprising:
a first step providing an optical waveguide allowing therethrough transmission of light from a light emitting element to a light receiving element which are electrically isolated from each other, the optical waveguide comprising a first bonding portion which connects a body and said light emitting element with each other, and a second bonding portion connecting said body and said light receiving element, said body being provided so as to extend from said light emitting element to said light receiving element, the body allowing transmission from the first bonding portion to the second bonding portion, and
a second step covering said optical waveguide with a resin containing a light reflective inorganic particle,
the steps being carried out in this order.
16. The method of manufacturing an optically coupled device according to claim 15 , wherein the resin contains 15-25% by weight of the reflective inorganic particle.
17. The method of manufacturing an optically coupled device according to claim 15 , wherein the reflective inorganic particle has a particle size of 25-35 nm.
18. The method of manufacturing an optically coupled device according to claim 15 , wherein the resin is a thermosetting epoxy resin.
19. The method of manufacturing an optically coupled device according to claim 15 , wherein the resin contains 50-60% by weight of silica.
20. The method of manufacturing an optically coupled device according to claim 15 , wherein said light reflective inorganic particle is a particle of at least any one species of inorganic material selected from titanium oxide, aluminum oxide, mica, aluminum nitride, and boron nitride.