Optical subassembly and optical module

1. An optical subassembly comprising:

an eyelet having a first surface, the eyelet having a second surface opposite to the first surface, the eyelet having a through-hole penetrating from the second surface to the first surface;

a support block made of ceramic in front of the first surface, the support block having a substrate mounting surface, the support block having a first side opposite to a surface in front of the first surface;

an element-mounted substrate on the substrate mounting surface, the element-mounted substrate having a first conductor pattern;

an optical element for converting an optical signal and an electric signal at least from one to another, the optical element mounted on the element-mounted substrate, the optical element being electrically connected to the first conductor pattern;

a pedestal made of metal and configured to be the same potential as the eyelet, the pedestal situated in front of the first surface;

a lead pin in the through-hole and for transmitting the electric signal; and

a relay board on the pedestal, the relay board having a second conductor pattern for transmitting the electric signal between the lead pin and the first conductor pattern,

wherein the support block has a metallization pattern that is electrically connected to the pedestal and is continuous from at least a part of the substrate mounting surface to at least a part of the first side.

2. The optical subassembly according to claim 1 , further comprising a first bonding wire connecting the pedestal and the metallization pattern, which is disposed on at least the part of the first side.

3. The optical subassembly according to claim 2 , wherein the first bonding wire includes two or more bonding wires.

4. The optical subassembly according to claim 1 , wherein the metallization pattern is not on a surface opposite to the substrate mounting surface.

5. The optical subassembly according to claim 1 , wherein the metallization pattern is not on the surface opposite to the first side.

6. The optical subassembly according to claim 1 , wherein

the element-mounted substrate has a ground pattern, and

the metallization pattern is electrically connected to the ground pattern.

7. The optical subassembly according to claim 1 , further comprising a second bonding wire connecting the first conductor pattern and the second conductor pattern.

8. The optical subassembly according to claim 1 , wherein the eyelet, the support block, and the element-mounted substrate are separated.

9. The optical subassembly according to claim 1 , wherein the eyelet and the pedestal are integrated.

10. The optical subassembly according to claim 1 , further comprising a castellation on a side of the element-mounted substrate.

11. The optical subassembly according to claim 10 , wherein the side of the element-mounted substrate is opposite to a surface, of the element-mounted substrate, facing the first surface of the eyelet.

12. The optical subassembly according to claim 11 , wherein the castellation is situated at a position equal to, or closer to the pedestal than, a position where the optical element is mounted, in a direction parallel to the first surface of the eyelet and parallel to the surface of the element-mounted substrate.

13. The optical subassembly according to claim 1 , wherein the pedestal and the support block are spaced.

14. The optical subassembly according to claim 1 , further comprising a temperature controller between the first surface of the eyelet and the support block.

15. An optical module comprising:

the optical subassembly according to claim 1 ;

a printed circuit board; and

a flexible printed circuit board electrically connected to the printed circuit board and the optical subassembly.