Optical module

Abstract

The application provides an optical module, which comprises a circuit board. Laser driving chips on driving chip bonding pads, flexible board bonding pads, and differential signal wires for connectingthe flexible board bonding pads with the driving chip bonding pads are arranged on a top signal layer of the circuit board. Ground holes for differential signal returning are formed around each groupof flexible board bonding pads, driving chip bonding pads, and differential signal wires on the top signal layer, and a first grounding layer and a second grounding layer in the circuit board, so that a signal return path is reduced. Moreover, metal layers are laid in forward projection areas of the flexible board bonding pads and hollow areas are formed in the forward projection areas of the driving chip bonding pads; and metal layers are laid in the forward projection areas of the driving chip bonding pads on the second grounding layer so as to provide a signal backflow ground. On the basisof the design, the high-frequency performance coherence resistance can be improved and thus the impedance continuity between the laser driving chip and the flexible circuit board in working of the optical module is improved.

Description

technical field [0001] The present application relates to the technical field of optical communication, and in particular to an optical module. Background technique [0002] The optical module is mainly used for photoelectric and electro-optical conversion. Its transmitting end converts electrical signals into optical signals and transmits them through optical fibers, and its receiving end converts received optical signals into electrical signals. [0003] In order to realize the above-mentioned photoelectric conversion function, a standard optical module usually includes components such as a circuit board, a light emitting sub-module and a light receiving sub-module connected to the circuit board. Among them, when the optical module has airtightness requirements in the actual use process, the light emitting sub-module will adopt an airtight box packaging structure, and the airtight box is packaged with optical devices such as lasers, and then the airtight box The airtight ...

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Problems solved by technology

[0004] However, as the transmission rate of the optical module increases, the impedance matching requirements between its internal components are also increasing, and the above-mentioned laser driver chip is welded on the Driver pad, and the flexible circuit board is soldered on the FPC pad. It is easy to have the problem of impedance discontinuity between the laser driver chip and the flexible circuit board, which in turn affects the signal quality of the emitted optical signal

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