Light-Emitting Device Cutout Electrodes for Resin Coverage Control
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Solution Overview
Problem
The use of masking tape to prevent resin flow into through-hole electrodes in surface-mounted LEDs can lead to increased resin material usage and cost, while suppressing resin coverage results in delamination and solder crawling issues during manufacturing, affecting mountability and die shear strength.
Innovation Solution
A light-emitting device with an insulating substrate featuring cutouts and separate wiring electrodes, covered by resin films, and a manufacturing method involving plating, wiring pattern formation, and individualization through dicing to prevent delamination and solder crawling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If masking tape is used to prevent resin flow into through-hole electrodes, then resin coverage is controlled, but resin material usage increases and cost rises
Solution Approach 1:
The patent divides the through-hole electrode structure into segments by forming resin non-contact portions at both ends of the through-hole electrodes. This segmentation allows the resin to be prevented from contacting specific critical regions while still covering other areas, thereby controlling resin coverage without requiring masking tape and reducing resin material usage.
Solution Approach 2:
The patent applies different resin coverage characteristics to different locations: resin is formed to cover side surfaces of the insulating substrate and portions of the through-hole electrodes, but deliberately excludes contact with the both ends of the through-hole electrodes. This local differentiation in resin coverage achieves precise control where needed while minimizing overall resin usage.
2Quantity of substance
If resin material is suppressed to not cover through-hole electrodes, then cost is reduced, but delamination occurs on exposed electrodes during dicing
Solution Approach 1:
The patent segments the resin coverage to distinguish between critical and non-critical regions. By forming resin non-contact portions only at both ends of the through-hole electrodes while maintaining resin coverage on side surfaces and other portions, the structure achieves both reduced resin usage and sufficient protection against delamination during dicing.
Solution Approach 2:
The patent performs preliminary action by pre-forming the resin non-contact portions at both ends of the through-hole electrodes before the dicing process. This preliminary configuration ensures that during subsequent dicing operations, the resin coverage is already optimized to prevent delamination on exposed electrodes while minimizing overall resin material usage.
3Quantity of substance
If through-hole electrodes are exposed to dicing surfaces, then resin material is reduced, but solder excessively crawls up through the holes during mounting
Solution Approach 1:
The patent applies local quality by creating resin non-contact portions specifically at both ends of the through-hole electrodes where solder crawling is most problematic. This localized resin absence combined with the overall resin coverage structure prevents excessive solder crawling during mounting while still reducing total resin material usage compared to complete coverage.
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
Improves mountability and reduces manufacturing failures by ensuring secure resin coverage and electrode integrity during individualization, enhancing the reliability of the light-emitting device.
Implementation Method 1
The first resin film covers a surface of each of the first wiring electrodes in each of regions that extend over edges along the one or the plurality of first cutouts in a top view viewed from a direction perpendicular to the upper surface of the substrate. The second resin film covers a surface of each of the second wiring electrodes in a region extending over edges along the one or the plurality of second cutouts in the top view.
Implementation Method 2
a first plating step of forming a copper layer on surfaces of the copper foil layers and inner surfaces of the plurality of through holes by plating
Implementation Method 3
an individualization step of individualizing by cutting the substrate structure so as to separate each of the plurality of through holes along dicing lines extending along the plurality of rows
Data Source
AI summary
A light-emitting device includes an insulating substrate having one or more first cutouts and one or more second cutouts provided on opposite side surfaces thereof. First and second wiring electrodes, which are separated from each other, correspond respectively to the first and second cutouts. The first and second wiring electrodes each cover a region that extends over an edge of the corresponding cutout on an upper surface of the substrate and a region that extends over an edge the corresponding cutout on a lower surface of the substrate from an internal surface of the cutout. First and second resin films cover surfaces the first and second wiring electrodes in regions that extend over edges along the first and second cutouts in a top view. A light-emitting element is placed on the substrate to allow power to be supplied by the first wiring electrode and the second wiring electrode.