Test and Transfer Structure for Optoelectronic Devices
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Solution Overview
Problem
Existing methods for testing and transferring unitary optoelectronic devices, such as LEDs, face challenges in detecting non-functional devices efficiently, particularly during the manufacturing process, as individualized devices are difficult to test and require additional steps that can lead to functional devices being identified late, increasing repair costs.
Innovation Solution
A test and transfer structure comprising a network of electrical interconnections with a contact pad and an electrically conductive sacrificial portion that can be etched to release the contact pad, allowing for both electrical testing and transfer of the device, enabling individual testing and transfer of contact pads efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If individual testing of optoelectronic devices is performed, then detection precision of faulty devices is improved, but device complexity and manufacturing process complexity increase
Solution Approach 1:
The patent divides the testing process into modular components: a test structure with contact pads that can be individually engaged with each optoelectronic device. Each contact pad is electrically connected to the test structure through a sacrificial portion, allowing independent electrical access to each device without requiring complex individualized test fixtures for each device.
Solution Approach 2:
The patent introduces a sacrificial portion as an intermediary element between the contact pad and the test structure. This sacrificial portion can be selectively removed to establish or break electrical connections, enabling individual device testing through a shared test structure without requiring permanent complex interconnections for each device.
2Productivity
If testing is performed early in the manufacturing process, then productivity is improved by preventing late detection, but reliability of detection worsens due to inability to detect later manufacturing defects
Solution Approach 1:
The test structure and contact pads are formed in advance on the donor substrate before the optoelectronic devices are fully manufactured and transferred. This preliminary preparation enables rapid individual testing of each device at the transfer stage, combining early process preparation with late-stage device verification to achieve both high productivity and reliable defect detection.
3Measurement precision
If additional test contacts are formed for each device, then measurement precision is improved, but manufacturing complexity and time increase
Solution Approach 1:
The patent merges multiple testing functions into a single integrated test structure that can simultaneously or sequentially test multiple optoelectronic devices. The contact pads are collectively formed on the donor substrate and can be individually engaged with each device through the sacrificial portion mechanism, eliminating the need for separate test contacts for each device and reducing manufacturing time.
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 allows for the efficient detection of faulty devices before transfer, reducing repair costs and simplifying the design of electronic devices by enabling individual testing and transfer of contact pads, improving the detection of faults occurring late in the manufacturing process.
Implementation Method 1
This sacrificial portion is designed to be etched to allow at least partial release of the contact pad
Data Source
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AI summary
The invention relates to a test and transfer structure (2) for contact pads (223) comprising a test portion (21) and a contact portion (22). The test portion (21) comprises at least one network of electrical interconnections (211, 213), and the contact portion (22) comprises at least one contact pad (223) at a contact face (200). This at least one contact pad is intended to be made in contact with at least one contact area (123) at a connection face (100) of an electronic device (1). The structure is characterized in that the contact portion (22) further comprises at least one electrically conductive sacrificial portion (225) electrically connecting the at least one contact pad (223) to the network of electrical interconnections (211, 213). The invention also relates to a test and transfer method implementing such a structure (2).