Optical semiconductor device, optical connector and electronic equipment

1. An optical semiconductor device, comprising:

a lead frame having at least two through holes;

at least one semiconductor optical element which has an optical portion and which is placed on one surface of the lead frame for the optical portion to face at least one of the through holes and overlap with the at least one of the through holes;

a first molding portion which covers the semiconductor optical element and which is made of a non-transparent molding resin placed on one surface of the lead frame; and

a second molding portion which covers the through hole and which is made of a transparent molding resin placed on the other surface of the lead frame, an expansion coefficient of the second molding portion being different from an expansion coefficient of the first molding portion, wherein

wherein, the first molding portion and the second molding portion make contact with one another through at least one of the at least two through holes, and

an area of a confronting surface of the second molding portion confronting the first molding portion is smaller than an area of a confronting surface of the first molding portion confronting the second molding portion.

2. The optical semiconductor device as defined in claim 1 , wherein

the at least one semiconductor optical element includes a light-emitting device and a light-receiving device, and further comprising:

a signal processing circuit part for the light-emitting device which is placed on the lead frame and which is electrically connected to the light-emitting device; and

a signal processing circuit part for the light-receiving device which is placed on the lead frame and which is electrically connected to the light-receiving device.

3. The optical semiconductor device as defined in claim 2 , wherein

the at least two through holes of the lead frame include a through hole for the light-emitting device confronting the light-emitting device and a through hole for the light-receiving device confronting the light-receiving device,

the second molding portion has a signal transmitting part which covers the through hole for the light-emitting device and a signal receiving part which covers the through hole for the light-receiving device, and

the signal transmitting part and the signal receiving part are separated from each other.

4. The optical semiconductor device as defined in claim 2 , wherein

the at least two through holes of the lead frame include a through hole for the light-emitting device confronting the light-emitting device and a through hole for the light-receiving device confronting the light-receiving device,

the second molding portion has a signal transmitting part which covers the through hole for the light-receiving device, a signal receiving part which covers the through hole for the light-receiving device, and a coupling portion which couples the signal transmitting part and the signal receiving part to each other, and

the coupling portion has a recessed portion.

5. The optical semiconductor device as defined in claim 2 , wherein

the signal processing circuit part for the light-emitting device and the signal processing circuit part for light-receiving device are included in one chip.

6. The optical semiconductor device as defined in claim 1 , further comprising:

a submount placed between the semiconductor optical element and the lead frame.

7. The optical semiconductor device as defined in claim 1 , further comprising

a buffering member which is made of an elastic resin having optical transparency and which is placed between the first molding portion and the second molding portion.

8. The optical semiconductor device as defined in claim 7 , wherein

the elastic resin of the buffering member is silicone resin having a glass transition temperature lower than a lowest operating temperature ensured by the optical semiconductor device.

9. The optical semiconductor device as defined in claim 1 , wherein

the semiconductor optical element includes a light-emitting device, and

the light-emitting device is a vertical cavity surface emitting laser.

10. The optical semiconductor device as defined in claim 1 , wherein

the molding resin of the second molding portion is an almost transparent resin containing a filler.

11. The optical semiconductor device as defined in claim 1 , wherein

the second molding portion has a lens.

12. The optical semiconductor device as defined in claim 6 , wherein

the semiconductor optical element includes a light-emitting device, and

the submount between the light-emitting device and the lead frame is a silicon submount having a tapered hole.

13. The optical semiconductor device as defined in claim 6 , wherein

the semiconductor optical element includes a light-receiving device, and

the submount between the light-receiving device and the lead frame is a glass submount.

14. The optical semiconductor device as defined in claim 1 , wherein

the molding resin of the first molding portion is subjected to curing process simultaneously with the molding resin of the second molding portion after molding process of the molding resin of the second molding portion.

15. The optical semiconductor device as defined in claim 1 , wherein

end portions of the second molding portion is chamfered.

16. An optical connector which includes the optical semiconductor device as defined in claim 1 .

17. Electronic equipment which includes the optical semiconductor device as defined in claim 1 .