Temporary-Substrate LED Arrays Without PCB Wire Bonding
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Solution Overview
Problem
The existing methods for creating LED arrays are complex and costly, particularly when mixing different types of light emitting devices, as they require separate bonding strategies and extensive die attach and wire bonding processes, which can lead to high failure rates and increased complexity in PCB or CCB fabrication.
Innovation Solution
A method that involves attaching LEDs to a carrier and temporary substrate, forming metal and insulator layers to create circuitry, and separating the array without the need for die attach or surface mounting, potentially eliminating the need for a PCB or CCB, and using metal interconnects to connect LEDs directly to electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate bonding strategies are used for different types of LEDs (VLEDs and PLEDs), then each LED type can be properly connected, but the manufacturing process complexity increases significantly
Solution Approach 1:
The patent applies universality by designing a single substrate structure that can accommodate both VLEDs and PLEDs with different electrode configurations. The substrate includes multiple bond pad arrangements that can universally connect to either vertical or planar LED types, eliminating the need for separate bonding strategies while maintaining reliable electrical connections for all LED variants.
Solution Approach 2:
The patent segments the substrate into distinct regions with different bond pad configurations, allowing each LED type to be connected to its appropriate segment. This segmentation enables mixed LED arrays where VLEDs connect to one pad type and PLEDs connect to another, simplifying the overall process by providing dedicated connection zones rather than requiring complex universal bonding procedures.
2Reliability
If extensive die attach and wire bonding processes are used to create LED arrays, then electrical connections are established, but the manufacturing cost and time increase
Solution Approach 1:
The patent merges the die attach and wire bonding functions into a single integrated process. The substrate design allows LEDs to be directly mounted with electrical connections established through integrated bond pads that combine both mechanical attachment and electrical connection functions, eliminating the need for separate wire bonding steps and significantly improving manufacturing efficiency.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the substrate with integrated bond pads before LED mounting. The bond pads are already positioned and configured to receive both mechanical and electrical connection functions, so when LEDs are mounted, both die attach and electrical connection are achieved in a single operation rather than requiring subsequent wire bonding steps.
3Reliability
If many small metal lines and via holes are formed in PCB or CCB, then electrical connections are achieved, but the fabrication complexity and cost increase
Solution Approach 1:
The patent extracts the complex metal line and via hole network from the PCB/CCB and relocates it to the LED array substrate. By forming the interconnect structure on the substrate itself rather than in the PCB, the design eliminates the need for numerous laser-drilled via holes and complex metal routing in the PCB, significantly simplifying PCB fabrication while maintaining reliable electrical connections.
Solution Approach 2:
The patent moves the interconnect structure from the two-dimensional PCB plane to the three-dimensional substrate structure. By utilizing vertical interconnections and layered metal structures on the substrate, the design achieves complex electrical routing without requiring corresponding complexity in the PCB, effectively transferring the manufacturing burden from PCB to substrate where it can be more efficiently implemented.
Data Source
AI summary
A method for making light emitting device LED arrays includes the steps of providing a plurality of LEDs having a desired configuration (e.g., VLED, FCLED, PLED); attaching the LEDs to a carrier substrate and to a temporary substrate; forming one or more metal layers and one or more insulator layers configured to electrically connect the LEDs to form a desired circuitry; and separating the LEDs along with the layered metal layers and insulator layers that form the desired circuitry from the carrier substrate and the temporary substrate.