Heat conducting member, optical module, heat sink, and method for preparing heat conducting member
A heat conducting member includes a substrate and a heat conducting layer. The substrate includes a heat conducting surface. The heat conducting layer includes a transition layer and a protective layer. The transition layer is disposed on the heat conducting surface, and the protective layer is disposed on a surface that is of the transition layer and that is away from the heat conducting surface. Roughness Ra of the protective layer is less than or equal to 0.4. The transition layer can provide a hardness transition function between the substrate and the protective layer, to facilitate improving overall hardness of the heat conducting member. The protective layer may ensure surface hardness, to prevent an undesirable situation such as a scratch.
1 . An optical network device comprising an optical module, a heat conducting layer and a heat sink, wherein the heat conducting layer is disposed on an upper surface of a housing of the optical module and is in direct contact with a lower surface of a base plate of the heat sink, wherein:
the heat conducting layer comprises a transition layer and a protective layer;
the transition layer is disposed on the upper surface of the housing;
the protective layer is disposed on a surface of the transition layer that is away from the heat conducting layer;
a surface roughness of the protective layer is less than or equal to 0.4 μm Ra;
a material of the transition layer is any one of nickel, chromium, or chromium nitride; and
a material of the protective layer is any one of diamond, diamond-like carbon, or amorphous alloy.
2 . The optical network device according to claim 1 , wherein a microhardness (HV) of the protective layer is greater than 1000.
3 . The optical network device according to claim 1 , wherein the heat conducting layer further comprises an auxiliary bonding layer; and
the auxiliary bonding layer is located between the transition layer and the protective layer, and is configured to improve bonding strength between the transition layer and the protective layer.
4 . The optical network device according to claim 3 , wherein a material of the auxiliary bonding layer is tungsten carbide or chromium carbide.
5 . The optical network device according to claim 1 , wherein the heat conducting layer further comprises an abrasive layer, the abrasive layer is located between the heat conducting layer and the transition layer, and the abrasive layer is a polishable layer.
6 . The optical network device according to claim 5 , wherein a material of the abrasive layer is copper or a copper alloy.
7 . The optical network device according to claim 5 , wherein a surface roughness of a surface of the abrasive layer and that is away from the heat conducting layer is less than or equal to 0.4 μm Ra.
8 . The optical network device according to claim 5 , wherein the heat conducting layer further comprises an auxiliary bonding layer; and
the auxiliary bonding layer is located between the heat conducting layer and the abrasive layer, and is configured to improve bonding strength between the heat conducting layer and the abrasive layer.
9 . The optical network device according to claim 8 , wherein a material of the auxiliary bonding layer is nickel or chromium.
10 . The optical network device according to claim 1 , wherein:
a surface roughness of the transition layer is a same as a surface roughness of the heat conducting layer; and
the die surface roughness of the protective layer is a same as the surface roughness of the transition layer.