Optical Device Package with Cutout Metal Base and Planar Wiring Board
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Solution Overview
Problem
In optical device headers, the long length of gold wires connecting semiconductor laser devices to leads increases transmission loss and prevents conformity in characteristic impedance, making it difficult to achieve the desired 50Ω impedance across the entire transmission path.
Innovation Solution
A metal base body with a cutout portion and a wiring board connected to its side surface, featuring an optical device mounting region and pads formed by patterning copper foil, allows for shorter wire connections between the optical device and pads, reducing transmission loss and achieving impedance conformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gold wires are used to connect semiconductor laser devices to leads in a traditional optical device header, then the connection is reliable, but the transmission loss increases and characteristic impedance conformity cannot be achieved
Solution Approach 1:
The patent transitions from a three-dimensional wire connection (gold wires extending vertically from the laser device to the leads) to a two-dimensional planar connection (copper foil traces on the wiring board surface). This dimensional change allows the connection path to be optimized for both length and impedance control, reducing transmission loss while maintaining reliability through the robust copper foil connection.
Solution Approach 2:
The patent changes the connection parameters by replacing gold wires with copper foil traces, altering the electrical characteristics of the transmission path. The copper foil provides lower resistance and better impedance control (achieving 50Ω conformity), which reduces transmission loss while maintaining reliable electrical connection between the optical device and external circuitry.
2Reliability
If glass sealing is used to seal leads on the eyelet, then air-tight sealing is achieved, but the manufacturing process becomes complicated and costs increase
Solution Approach 1:
The patent extracts and eliminates the glass sealing component and process from the traditional optical device header structure. By removing the eyelet and glass sealing assembly, the design achieves air-tight sealing through alternative means (likely through the integrated wiring board structure and conformal coating), thereby simplifying the manufacturing process while maintaining sealing reliability.
Solution Approach 2:
The patent merges the sealing function with the wiring board structure itself. Instead of using a separate glass sealing layer, the wiring board and its mounting structure integrate the sealing function, eliminating the need for distinct glass sealing components and processes while achieving the same air-tight protection for the mounted optical devices.
Data Source
AI summary
An optical device package includes a metal base body including a cutout portion formed from an outer circumferential surface of the metal base body toward the center portion thereof, and a wiring board connected on a side surface of the cutout portion of the metal base body. The wiring board includes an optical device mounting region provided on a portion of the wiring board located inside the cutout portion of the metal base body, and a pad arranged on a portion of the wiring board located outside the optical device mounting region.