Optical Probe Package Structure for Wafer-Level Testing
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Solution Overview
Problem
Current methods for inspecting flat optical components on wafers are inefficient, costly, and lack accuracy, particularly in achieving optimal coupling efficiency and alignment, which hinders mass production and increases product development cycles.
Innovation Solution
An optical probe package structure with a mode field conversion waveguide and V-shaped grooves for precise optical fiber positioning, allowing for total reflection and efficient coupling of optical signals to uncut wafers, matching the propagation field of optical chips, and enabling accurate alignment and high-speed testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If grating structure is used for surface coupling light, then light coupling is achieved, but coupling efficiency is difficult to improve and requires special structures increasing cost and size
Solution Approach 1:
The patent extracts the grating structure from the coupling mechanism and replaces it with a direct end-face coupling approach. The optical probe package directly couples light to the optical chip end-face without requiring grating structures, thereby simplifying the overall structure while maintaining coupling efficiency.
Solution Approach 2:
Instead of using surface coupling with grating structures as in conventional approaches, the patent inverts the coupling approach by using end-face coupling. The optical probe package couples light directly to the end-face of the optical chip, reversing the traditional surface coupling methodology and achieving better alignment accuracy without complex structures.
2Measurement precision
If wafer is cut and polished before detection, then end-coupled optical components can be detected, but detection is costly and time-consuming
Solution Approach 1:
The patent implements preliminary detection by enabling optical probing of uncut wafers before the cutting and polishing processes. The optical probe package can detect optical components on wafers in their raw, unprocessed state, allowing for early verification and feedback in the manufacturing process, thereby reducing development time and costs.
3Adaptability or versatility
If manual coupling is used for testing, then structure testing is possible, but testing efficiency is low and structures that can be tested are greatly limited
Solution Approach 1:
The patent implements self-alignment mechanisms where the optical probe package automatically aligns with the optical chip end-face using V-shaped grooves and mode field conversion. This eliminates the need for manual coupling operations, significantly improving testing efficiency while maintaining the ability to test various optical structures through automated positioning.
4Measurement precision
If fiber array connector is used to align light coupling, then surface coupling is achieved, but vertical coupling accuracy requires special structures increasing cost and size
Solution Approach 1:
The patent replaces the mechanical fiber array connector system with an optical field-based alignment approach. Mode field conversion is used to achieve automatic alignment between the optical probe package and the optical chip end-face, substituting mechanical positioning with optical field matching, thereby improving vertical coupling accuracy without additional mechanical structures.
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 solution reduces production costs and cycles, enhances detection accuracy, and supports mass production by ensuring precise alignment and efficient coupling of optical signals to optical chips on uncut wafers, improving the overall testing process.
Implementation Method 1
the facet has a facet angle to generate total reflection of the optical signal transmitted by the optical fiber
Data Source
AI summary
An optical probe package structure is provided, used in a test environment for testing a plurality of optical chips on a wafer, including: a main body, an optical fiber, an optical fiber positioning area, a mode field conversion waveguide structure, and an optical waveguide. Wherein, the mode field conversion waveguide structure is used to convert the propagation field of the optical signal, and the optical signal transmitted by the mode field conversion waveguide structure enters the optical waveguide. The optical waveguide has an emitting end, and the emitting end is provided with a facet, the facet has a facet angle, and the facet angle makes the optical signal after field conversion mode field conversion to produce total reflection and output along a second direction. The optical signal after total reflection enters the optical chips. Thereby, an optical probe package structure that can test before wafer cutting and polishing is provided.