Optical element-mounting substrate and method of producing the same
An optical element-mounting substrate that makes it easy to optically couple the optical semiconductor element to the optical fiber or to the lens and that can be highly integrated while suppressing deterioration in the high-frequency signals. The optical element-mounting substrate for optically coupling the optical semiconductor element to the optical fiber through the lens, comprises an insulating film formed on the surface of the optical element-mounting substrate, grooves formed on the substrate for installing the optical fiber and the lens, a thin-film electrode formed on the insulating film, a thin-film capacitor and a thin-film temperature sensor arranged maintaining a distance from the thin-film electrode, and a solder film formed on the insulating film in a region where the optical semiconductor element is mounted so as to be electrically connected to the thin-film electrode.
1. An optical element-mounting substrate comprising:
a substrate;
a thin-film electrode formed on said substrate; and
a filter circuit formed on said substrate,
wherein said filter circuit comprises at least a first thin-film resistor or a thin-film capacitor, said substrate further comprising:
a temperature sensor formed on said substrate; and
an optical fiber holding portion formed on said substrate;
wherein said substrate includes a region to mount said optical element, and
wherein said at least a first thin-film resistor or said thin-film capacitor is formed across a line, connecting said optical fiber to said region, from said temperature sensor.
2. An optical element-mounting substrate according to claim 1 , said substrate further comprising:
a thin-film temperature sensor formed on said substrate; and
a solder-film formed on a region to mount an optical element,
wherein said thin-film electrode and said solder-film are connected to each other,
wherein said substrate is comprised of at least silicon, and
wherein said optical fiber holding portion comprises a groove formed on said substrate.
3. An optical element-mounting substrate according to claim 2 ,
wherein a lens holding groove is formed on said substrate.
4. An optical element-mounting substrate according to claim 2 ,
wherein said thin-film temperature sensor comprises:
a first thin-film electrode;
a second thin-film electrode; and
a second thin-film resistor,
wherein said first thin-film electrode is electrically connected to one end of said second thin-film resistor and said second thin-film electrode is electrically connected to another end of said second thin-film resistor.
5. An optical element-mounting substrate according to claim 4 ,
wherein said first thin-film electrode and said second thin-film electrode cover a portion of said second thin-film resistor.
6. An optical element-mounting substrate according to claim 4 ,
wherein said second thin-film resistor covers a portion of said first thin-film electrode and said second thin-film electrode.
7. An optical element-mounting substrate according to claim 4 ,
wherein said first thin-film electrode and said second thin-film electrode cover a portion of said second thin-film resistor.
8. An optical element-mounting substrate according to claim 4 ,
wherein said second thin-film resistor covers a portion of said first thin-film electrode and said second thin-film electrode.
9. An optical element-mounting substrate according to claim 2 ,
wherein said thin-film temperature sensor comprises:
a first thin-film electrode;
a second thin-film electrode; and
a second thin-film resistor,
wherein said first thin-film electrode is electrically connected to one end of said second thin-film resistor and said second thin-film electrode is electrically connected to another end of said second thin-film resistor.
10. An optical element-mounting substrate according to claim 1 ,
said substrate further comprising:
a holding portion formed on said substrate,
wherein said holding portion holds at least a lens.
11. An optical element-mounting substrate according to claim 1 ,
wherein said temperature sensor is a thin-film temperature sensor, and
wherein said thin-film temperature sensor comprises:
a first thin-film electrode;
a second thin-film electrode; and
a second thin-film resistor,
wherein said first thin-film electrode is electrically connected to one end of said second thin-film resistor and said second thin-film electrode is electrically connected to another end of said second thin-film resistor electrically.
12. An optical element-mounting substrate according to claim 11 ,
wherein at least one of said thin-film resistor, said thin-film capacitor and said thin-film temperature sensor is comprised of a nitride of tantalum.
13. An optical element-mounting substrate according to claim 1 ,
wherein said line is a substantially straight line.
14. An optical element-mounting substrate comprising:
a substrate to optically couple an optical semiconductor element to an optical fiber through a lens, wherein said substrate is comprised of at least silicon;
a groove portion formed substantially along one crystalline surface of said silicon to mount said lens;
a thin-film electrode;
a filter circuit comprising a resistor and a capacitor;
a temperature sensor;
a wire connecting region to connect an end of a wire connected from an external unit; and
an optical semiconductor element mounting region;
wherein said thin-film electrode, said filter circuit, said temperature sensor, said wire connecting region and said optical semiconductor mounting region are formed on said substrate surrounding said groove portion, and
wherein said capacitor comprises at least a thin-film capacitor electrode or thin-film dielectric,
wherein said thin-film electrode is connected between said wire connecting region and said optical semiconductor element mounting region,
wherein said optical semiconductor element and said optical fiber are located along a line, and
wherein said wire connecting region, said resistor and said capacitor are formed across the line from said temperature sensor.
15. An optical element-mounting substrate according to claim 14 ,
wherein at least one of said resistor, said capacitor and said temperature sensor is comprised of a nitride of tantalum.
16. An optical element-mounting substrate according to claim 14 , wherein said line is a substantially straight line.
17. An optical element-mounting substrate comprising:
a substrate to optically couple an optical semiconductor element to an optical fiber through a lens, wherein said substrate is comprised of silicon;
a groove portion formed said substrate to mount at least said lens;
a filter circuit comprising a resistor and a capacitor;
a thin-film temperature sensor;
an optical semiconductor element mounting region;
a light-receiving element mounting region for mounting a light-receiving element; and
a first thin-film electrode and a second thin-film electrode to connect to said light-receiving element;
wherein said filter circuit, said thin-film temperature sensor, said optical semiconductor element mounting region, said light-receiving element mounting region, said first thin-film electrode and said second thin-film electrode are formed on said substrate surrounding said groove portion, and
wherein said filter circuit comprises at least a thin-film resistor or a thin-film capacitor,
wherein said optical semiconductor element mounting region and said light-receiving element mounting region are located along a line, and
wherein said thin-film temperature sensor are formed on the side of said first thin-film electrode which is across the line from said resistor and said capacitor on the side of said second thin-film electrode.
18. An optical element-mounting substrate comprising:
a substrate to optically couple an optical semiconductor element to an optical fiber;
a insulating film formed on said substrate;
a holding portion to hold at least said optical fiber or a lens, wherein said holding portion is formed on said substrate;
a thin-film resistor formed on said insulating film;
a thin-film capacitor arranged to maintain a gap from said thin-film resistor;
a wire connecting region to connect an end of a wire connected from an external unit;
an optical semiconductor element mounting region;
a light-receiving element mounting region; and
a thin-film electrode to connect between said wire connecting region and said optical semiconductor element mounting region;
wherein at least either said thin-film resistor or said thin-film capacitor is so arranged to be substantially surrounded by regions of said thin-film electrode with a gap being provided between said thin-film resistor or said thin-film capacitor and said regions of said thin-film electrode.
19. An optical element-mounting substrate according to claim 18 , said substrate further comprising:
a thin-film temperature sensor formed on said substrate; and
a solder-film formed on a region to mount said optical element,
wherein said thin-film electrode and said solder-film are connected to each other,
wherein said substrate is comprised of at least silicon, and
wherein said optical fiber holding portion comprises a groove formed on said substrate.
20. An optical element-mounting substrate according to claim 19
wherein at least one of said first thin-film resistor, said thin-film capacitor and said thin-film temperature sensor is comprised of a nitride of tantalum.
21. An optical element-mounting substrate according to claim 19 ,
wherein a lens holding groove is formed on said substrate.
22. An optical element-mounting substrate according to claim 19 ,
wherein said thin-film temperature sensor comprises:
a first thin-film electrode;
a second thin-film electrode; and
a second thin-film resistor,
wherein said first thin-film electrode is electrically connected to one end of said second thin-film resistor and said second thin-film electrode is electrically connected to another end of said second thin-film resistor.
23. An optical element-mounting substrate according to claim 22 ,
wherein said first thin-film electrode and said second thin-film electrode cover a portion of said second thin-film resistor.
24. An optical element-mounting substrate according to claim 22 ,
wherein said second thin-film resistor covers a portion of said first thin-film electrode and said second thin-film electrode.
25. An optical element-mounting substrate comprising:
a substrate to optically couple an optical semiconductor element to an optical fiber;
a insulating film formed on said substrate;
a holding portion to hold at least a lens, wherein said holding portion is formed on said substrate;
a thin-film resistor;
a thin-film capacitor; and
a thin-film electrode to connect between said thin-film resistor and said thin-film capacitor,
wherein said thin-film resistor, said thin-film capacitor and said thin-film electrode are formed on said insulating film surrounding said holding portion.
26. An optical element-mounting substrate according to claim 25 , said substrate further comprising:
a thin-film temperature sensor formed on said substrate; and
a solder-film formed on a region to mount said optical element,
wherein said thin-film electrode and said solder-film are connected to each other,
wherein said substrate is comprised of at least silicon, and
wherein said holding portion comprises a groove formed on said substrate.
27. An optical element-mounting substrate according to claim 26 ,
wherein at least one of said first thin-film resistor, said thin-film capacitor and said thin-film temperature sensor is comprised of a nitride of tantalum.