an optical module

Abstract

The application provides an optical module, the optical module includes a circuit board, and the top signal layer of the circuit board has a laser driver chip on a driver chip pad, a flexible board pad, a connection flex board pad and a driver chip pad differential signal traces. At the same time, on the top signal layer, the first ground layer, and the second ground layer in the circuit board, around each group of flexible board pads, driver chip pads, and differential signal traces, there are ground holes for differential signal reflow. Furthermore, the signal return path can be shortened, and, on the first ground layer, a metal layer is laid on the forward projection area of ​​the flexible board pad and a hollowed out area is opened in the forward projection area of ​​the driver chip pad, and the second ground layer On the layer, a metal layer is laid on the forward projection area of ​​the driver chip pad to provide a signal return ground. Through the above design, the anti-continuity of high-frequency performance can be improved, and then the impedance continuity between the laser driver chip and the flexible circuit board can be improved when the optical module is working.

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 ...

AI Technical Summary

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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