Thin Light Emitting Device via Temporary Substrate Removal
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Solution Overview
Problem
Current light emitting devices are not thin enough to reduce the size of products in which they are installed, necessitating a method to manufacture thinner devices.
Innovation Solution
A method involving a first intermediate body with a temporary substrate and a light emitting element connected via solders, followed by removal of the temporary substrate to form a second intermediate body with external connection electrodes, achieving a reduced thickness by grinding the lower surface to create a planar surface for the electrodes and solders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a temporary substrate is used to mount the light emitting element during manufacturing, then the light emitting element can be securely positioned and connected via solders, but the overall device thickness increases
Solution Approach 1:
The temporary substrate is completely removed after the light emitting element is mounted and connected via solders. This extraction eliminates the thickness contribution of the temporary substrate from the final device structure, resolving the contradiction between needing secure mounting during manufacturing and achieving thin final device thickness.
Solution Approach 2:
The light emitting element is mounted and electrically connected to the temporary substrate before the substrate removal step. This preliminary mounting action ensures proper positioning and electrical connections are established while the temporary substrate is still present, allowing subsequent removal without compromising the mounted element's stability or connections.
2Length of moving object
If the temporary substrate is removed to reduce thickness, then the device becomes thinner, but the lower surface becomes non-planar
Solution Approach 1:
Mechanical grinding is used to remove material from the non-planar lower surface and replace it with a planar surface. This mechanical substitution transforms the irregular surface geometry into a flat, planar surface suitable for mounting external connection electrodes, resolving the contradiction between thickness reduction and surface planarity.
Solution Approach 2:
The surface geometry parameter is changed from non-planar to planar through grinding. This parameter change transforms the surface characteristics to enable proper electrode mounting while maintaining the reduced thickness achieved by substrate removal.
3Ease of manufacture
If grinding is performed on the lower surface to create a planar surface, then external connection electrodes can be properly mounted, but additional manufacturing steps are required
Solution Approach 1:
The manufacturing process is segmented into distinct sequential steps: mounting the light emitting element on the temporary substrate, removing the temporary substrate, grinding the lower surface to create planarity, and mounting external connection electrodes. This segmentation organizes the complex process into manageable stages, making the overall manufacturing easier to control and execute despite the multiple steps involved.
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
The method allows for the production of thin light emitting devices with improved heat dissipation and reduced thickness, suitable for various applications including backlight devices and lighting fixtures.
Implementation Method 1
a light emitting element disposed on the first wirings and including an electrode-formation surface and a pair of element electrodes formed on the electrode-formation surface, each of the pair of element electrodes connected to a respective one of the first wirings via a respective one of a plurality of solders
Implementation Method 2
removing a portion of the temporary substrate at a first lower surface side of the base to form a second intermediate body having a second lower surface
Data Source
AI summary
The method of manufacturing a light emitting device includes: providing a first intermediate body, the first intermediate body including a temporary substrate including a base and a pair of first wirings, and a light emitting element including a pair of element electrodes, each of the pair of element electrodes connected to a respective one of the first wirings via a respective one of a plurality of solders; removing a portion of the temporary substrate to form a second intermediate body having a second lower surface in which a lower surface of each of the element electrodes and a lower surface of each of the plurality of solders are located; and forming a pair of external connection electrodes on the second lower surface such that each of the pair of external connection electrodes cover a respective one of the element electrodes and a respective one of the plurality of solders.