FPC-Attached Optical Modulator With Side Metal Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical modulators, the reduction in size of pads on flexible printed circuits (FPCs) leads to variations in connection states between electrodes and pads on the circuit substrate, affecting radio frequency propagation characteristics and degrading the quality of modulated light output.
Innovation Solution
The optical modulator incorporates a flexible printed circuit with metal films connecting pads on opposite surfaces through thermally conductive through-holes and recessed areas on the side surface, ensuring stable solder connections and uniform radio frequency propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the size of pads on FPC is reduced, then the installation space is decreased, but the connection state between electrodes and pads varies, degrading RF propagation characteristics
Solution Approach 1:
The patent applies local quality by providing metal films on the side surface of the FPC specifically at pad locations. These metal films locally enhance the connection area and solderability without increasing the overall pad size, thereby maintaining connection reliability while keeping the FPC compact.
Solution Approach 2:
The patent transitions from a two-dimensional pad structure to a three-dimensional structure by adding metal films on the side surface of the FPC. This dimensional extension increases the effective connection area without increasing the planar footprint, resolving the contradiction between small pad size and reliable connection.
2Area of stationary object
If the size of pads on FPC is reduced, then the installation space is decreased, but the radio frequency propagation characteristics are affected
Solution Approach 1:
Metal films are locally applied on the side surface of the FPC at pad positions to enhance RF signal integrity. This local enhancement improves RF propagation characteristics without requiring larger pads, thus maintaining the compact design while ensuring manufacturing precision for RF applications.
Solution Approach 2:
The patent uses composite structures combining the FPC substrate material with metal films on the side surface. This composite approach leverages the advantages of both materials: the flexibility and compactness of FPC and the excellent RF properties and solderability of metal films, thereby maintaining RF propagation characteristics in a compact design.
3Reliability
If metal films are added on the side surface of FPC, then the connection reliability is improved, but the device complexity increases
Solution Approach 1:
Metal films are applied only on the side surface at specific pad locations rather than throughout the entire FPC structure. This localized approach improves solder connection stability while minimizing the increase in device complexity, as the metal films are confined to specific functional areas.
Solution Approach 2:
The metal films on the side surface automatically serve multiple functions: they enhance solderability, provide mechanical support for solder joints, and improve RF signal integrity. This self-service capability of the metal films reduces the need for additional separate components or complex assembly processes, thereby limiting the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration stabilizes radio frequency propagation characteristics by ensuring consistent solder connections and reducing variations in connection states, enhancing the optical transmission quality.
Implementation Method 1
The flexible printed circuit includes through-holes that thermally connect the plurality of first pads to the plurality of second pads
Data Source
AI summary
An optical modulator including a flexible printed circuit performing an electrical connection with an external circuit substrate, in which the flexible printed circuit includes a plurality of first pads and the like provided on one surface of the flexible printed circuit along one side of the flexible printed circuit, a plurality of second pads and the like provided on the other surface of the flexible printed circuit at locations that respectively correspond to the plurality of first pads, and a plurality of metal films and the like provided at locations that respectively correspond to the first pads on a side surface of the flexible printed circuit along the one side of the flexible printed circuit.