Endoscope Optical Module Hermetic Sealing via Solder Ring Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in developing an optical module for endoscopes is to create a compact, reliable, and high-productivity solution for optical signal transmission using optical fibers, while ensuring hermetic sealing and efficient manufacturing processes, especially with the increasing number of pixels in image pickup devices, which demands improved signal transmission methods.
Innovation Solution
The optical module incorporates an optical fiber, an optical element with a light emitting or receiving section, a first substrate with an insertion hole for the fiber, and a second substrate with a recessed section housing the element, bonded together using a solder ring that forms a seal, enabling electrical connection through a connection electrode and through-wire, facilitating efficient wafer-level manufacturing and singulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If an optical module is miniaturized to reduce endoscope diameter, then the endoscope size is reduced, but hermetic sealing becomes more difficult to achieve
Solution Approach 1:
The optical module is divided into two separate substrates (first substrate with optical element and second substrate with recessed section) that are bonded together. This segmentation allows each substrate to be optimized independently while maintaining hermetic sealing through the bonding interface, resolving the contradiction between miniaturization and sealing reliability.
Solution Approach 2:
The optical element is housed within a recessed section of the second substrate, creating a nested structure where the optical element is contained within the substrate cavity. This nesting approach enables compact packaging while maintaining hermetic sealing, as the recessed section provides a protected environment for the optical element.
2Productivity
If wafer-level manufacturing is used to improve productivity, then manufacturing efficiency increases, but hermetic sealing and reliability become more challenging
Solution Approach 1:
Multiple optical modules are manufactured simultaneously on wafer substrates before final singulation. The first and second substrates are prepared and bonded at the wafer level, establishing hermetic seals in advance. This preliminary action enables high-volume manufacturing while maintaining sealing integrity, as the wafer-level bonding process creates reliable seals that are then preserved during subsequent cutting and singulation operations.
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 results in a small, reliable, and high-productivity optical module with enhanced optical coupling efficiency, resistance to high-temperature and humidity tests, and improved reliability, suitable for endoscopes with image pickup devices having a large number of pixels.
Implementation Method 1
a solder ring that bonds the first substrate and the second substrate
Implementation Method 2
an optical fiber configured to transmit an optical signal
Implementation Method 3
The external terminal of the optical element is electrically connected to the lower electrode via the connection electrode, the seal ring, the solder ring, the guard ring, and the through-wire
Data Source
AI summary
An optical module for endoscope includes an optical fiber, an optical element, a first substrate including, on a first principal plane, an insertion hole into which the optical fiber is inserted, the optical element being mounted on a second principal plane of the first substrate, a second substrate, on a third principal plane of which a recessed section in which the optical element is housed is present, and a solder ring that bonds a seal ring of the second principal plane of the first substrate and a guard ring of the third principal plane of the second substrate. The first substrate and the second substrate have the same external dimension in an optical axis orthogonal direction, and side surfaces of the first substrate and the second substrate are present in the same plane.