An optical device includes a base of ring shape, and an optical chip and a transparent plate both attached to the base. The upper surface of the base is formed with a tapered recess inclined downwardly from its flat portion toward the opening. A gap between the tapered recess and the transparent plate is formed with an adhesive layer. Even if a gap between the transparent plate and the flat portion of the base is narrowed, the adhesive layer with a great thickness present between the tapered recess and the lower surface of the transparent plate maintains the mechanical adhesion strength between the base and the transparent plate. A raised ring and a recessed ring prevent adhesive from entering a positioning hole and the opening.
1. An optical device comprising:
a base of ring shape with a tapered recess surrounding an opening;
an optical chip mounted so that a main surface thereof with an optical element disposed is exposed within the opening of the base when viewed from above;
a transparent member attached above an upper surface of the base; and
an adhesive layer provided in a gap between the base and the transparent member,
wherein the upper surface of the base has a taper so that the thickness of the base becomes thin toward the opening in the tapered recess, and
in the region of the tapered recess except for an inner surface of the opening, the distance from a portion of the tapered recess that is located in the upper surface of the base and is joined with the inner surface of the opening to the bottom of the base is smaller than the distance from a portion of the tapered recess that is located in the upper surface of the base other than the portion of the tapered recess that is joined with the inner surface of the opening to the bottom of the base.
2. The device of claim 1 ,
wherein the upper surface of the base where the tapered recess is formed has a surface roughness Rz of 5 to 35μm.
3. The device of claim 1 ,
wherein the upper surface of the base has a raised ring at a location a predetermined distance outwardly away from just below the side edge of the transparent member.
4. The device of claim 3 ,
wherein the inner side wall of the raised ring has the function of stemming a flow of adhesive forming the adhesive layer while the outer side wall thereof has the function of determining the position at which a member to be annexed onto the optical device is attached.
5. The device of claim 1 ,
wherein the upper surface of the base has a recessed ring at a location a predetermined distance outwardly away from just below the side edge of the transparent member.
6. The device of claim 1 ,
wherein the base is provided with a positioning hole serving as a reference to the position at which a member to be annexed onto the optical device is attached.
7. The device of claim 1 ,
wherein the optical element comprises a light receiving element and a light emitting element, and
the transparent member is a hologram.
8. The device of claim 1 ,
wherein the transparent member is a transparent plate.
9. The device of claim 1 , wherein
a wire is formed on a back surface of the base.
10. An optical device comprising:
a base of ring shape with a tapered recess surrounding an opening;
an optical chip mounted so that a main surface thereof with an optical element disposed is exposed within the opening of the base when viewed from above;
a transparent member attached above an upper surface of the base; and
an adhesive layer filling a gap between the base and the transparent member,
wherein the upper surface of the base extending outwardly a predetermined distance from just below the side edge of the transparent member has a surface roughness Rz of 5 to 35μm, and
in the region of the tapered recess except for an inner surface of the opening, the distance from a portion of the tapered recess that is located in the upper surface of the base and is joined with the inner surface of the opening to the bottom of the base is smaller than the distance from a portion of the tapered recess that is located in the upper surface of the base other than the portion of the tapered recess that is joined with the inner surface of the opening to the bottom of the base.
11. The device of claim 10 ,
wherein the base is provided with a positioning hole serving as a reference to the position at which a member to be annexed onto the optical device is attached.
12. The device of claim 10 ,
wherein the optical element comprises a light receiving element and a light emitting element, and
the transparent member is a hologram.
13. The device of claim 10 ,
wherein the transparent member is a transparent plate.
14. An optical device comprising:
a base of ring shape with a tapered recess surrounding an opening;
an optical chip mounted so that a main surface thereof with an optical element disposed is exposed within the opening of the base when viewed from above;
a transparent member attached above the upper surface of the base; and
an adhesive layer filling a gap between the base and the transparent member,
wherein the upper surface of the base has a raised ring at a location a predetermined distance outwardly away from just below the side edge of the transparent member,
the outer side wall of the raised ring has the function of the determining the position at which a member to be annexed onto the optical device is attached,
in the region of the tapered recess except for an inner surface of the opening, the distance from a portion of the tapered recess that is located in the upper surface of the base and is joined with the inner surface of the opening to the bottom of the base is smaller than the distance from a portion of the tapered recess that is located in the upper surface of the base other than the portion of the tapered recess that is joined with the inner surface of the opening to the bottom of the base.
15. The device of claim 14 ,
wherein the inner side wall of the raised ring has the function of stemming a flow of adhesive forming the adhesive layer.
16. The device of claim 14 , wherein
the optical element comprises a light receiving element and a light emitting element, and
the transparent member is a hologram.
17. The device of claim 14 , wherein
the transparent member is a transparent plate.
18. The device of claim 14 , wherein
the upper surface of the base has a taper so that the thickness of the base becomes thin toward the opening.
19. The device of claim 14 , wherein
the upper tapered recess is just below the transparent member.
20. The device of claim 19 , wherein
the tapered recess is filled with the adhesive layer.
21. The device of claim 14 , wherein
the upper surface of the base extending outwardly a predetermined distance from just below the side edge of the transparent member has a surface roughness Rz of 5 to 35μm.