Bridge Beam Optical Probe Alignment for Wafer Testing
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Solution Overview
Problem
Existing semiconductor device testing apparatuses struggle to position optical interfaces with high precision relative to optical deflection elements due to simultaneous changes in the relative positions of contact pads and optical interfaces during wafer positioning.
Innovation Solution
A bridge beam with a first actuator that moves an optical probe relative to a semiconductor device, allowing independent adjustment of the optical probe's position, and optionally includes a holder, optical detection portion, and second actuator for precise alignment, with six degrees of freedom in XYZ directions and roll, pitch, and yaw, enabling high-precision positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the positioning stage is driven to position the wafer, then the contact pad and optical interface are positioned simultaneously, but the relative position of the optical interface with respect to the optical deflection element cannot be changed independently, resulting in low positioning precision
Solution Approach 1:
The patent divides the positioning function into two independent parts: the positioning stage for positioning the wafer (contact pad and optical interface simultaneously), and the bridge beam with actuator for independently positioning the optical probe relative to the optical deflection element. This segmentation allows each component to perform its specific positioning function without interference from the other.
Solution Approach 2:
The bridge beam acts as an intermediary mechanism between the positioning stage and the optical probe. It provides an additional degree of freedom that decouples the optical probe positioning from the wafer positioning, enabling independent adjustment of the optical interface relative to the optical deflection element while the wafer remains positioned by the positioning stage.
2Measurement precision
If a bridge beam with first actuator is added to move the optical probe independently, then high-precision positioning of optical probe is enabled, but the device complexity increases
Solution Approach 1:
The patent combines the optical probe, holder, first actuator, and optical detection portion into a single integrated bridge beam structure. This merging reduces the overall system complexity compared to having separate independent positioning mechanisms, while still providing the necessary independent positioning capability for the optical probe.
Solution Approach 2:
The bridge beam serves multiple functions: it holds the optical probe, provides positioning via the first actuator, supports the optical detection portion, and enables both optical and electrical testing. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
3Measurement precision
If the first actuator provides six degrees of freedom for positioning, then the optical probe can be positioned with high precision in all directions, but the control complexity increases
Solution Approach 1:
The patent incorporates an optical detection portion that detects the optical signal and provides feedback to the control device. This feedback mechanism enables automatic adjustment of the first actuator to achieve precise positioning of the optical probe, reducing the manual control complexity despite the six degrees of freedom.
Solution Approach 2:
The system uses the optical detection portion to automatically detect and verify the positioning status of the optical probe, allowing the control device to autonomously adjust the first actuator without requiring complex manual intervention. The system essentially positions itself with high precision through automated feedback control.
Data Source
AI summary
A bridge beam attached to a semiconductor device handling apparatus that handles a semiconductor device, includes a beam-shaped main body to which a probe card is attached. The probe card has a contact that is electrically connected to a terminal of the semiconductor device. The bridge beam includes a first actuator, attached to the beam-shaped main body, that moves an optical probe relative to the semiconductor device. The optical probe performs one or both of emitting an optical signal to the semiconductor device and receiving the optical signal from the semiconductor device.