LED Chip Sidewall Geometry for Stable Light Module Mounting

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods of dicing light emitting diodes result in chips with irregularly inclined side surfaces, leading to rotation and improper mounting on substrates, causing irregular beam angles and handling issues.

Innovation Solution

A method involving laser irradiation to form modified and ruptured regions on the substrate, ensuring uniform luminance by controlling the angles of the side surfaces of the chips, using femto-second lasers to minimize thermal damage and adjust the width of these regions for precise cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional laser cutting is used to dice wafers into light emitting chips, then the dicing process can be completed, but the chips have irregularly inclined side surfaces causing rotation and improper mounting

Engineering Contradiction:

Improvedicing efficiencyVSAvoidside surface angle uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the laser processing parameters by using femto-second laser pulses with specific pulse widths (10^-15 seconds) and energies to create modified regions that result in perpendicular side surfaces. The laser pulse duration and energy density are optimized to achieve precise cutting without thermal diffusion, producing uniform 90-degree angles on chip side surfaces.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions of the wafer material through femto-second laser irradiation, creating modified regions that undergo structural changes. The laser induces localized phase transitions in the crystal lattice, forming modified regions that guide crack propagation to produce clean, perpendicular cuts without melting or thermal damage to surrounding areas.

Inventive Principle:

Principle #36Phase transitions

2Productivity

If conventional dicing methods are used, then chips can be produced, but thermal damage occurs and side surfaces are irregular

Engineering Contradiction:

Improvechip production rateVSAvoidthermal damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic femto-second laser pulses to dice the wafer. The pulsed nature of the laser delivery allows for periodic energy input that creates modified regions without cumulative thermal damage. The pulse frequency and duty cycle are optimized to maintain material integrity while achieving complete separation of chips.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The femto-second laser pulses deliver energy so rapidly that the laser interaction time is shorter than the thermal diffusion time. This 'skips' through the material faster than heat can spread, creating modified regions and inducing cracks without thermal damage to adjacent areas, thus preserving material quality while maintaining high production rates.

Inventive Principle:

Principle #21Skipping (Rushing through)

3Ease of operation

If chips with inclined side surfaces are mounted, then mounting can proceed, but rotation occurs and beam angles become irregular

Engineering Contradiction:

Improvemounting processVSAvoidmounting stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent performs preliminary laser modification and cutting to create chips with perpendicular side surfaces before mounting. By establishing the correct geometric configuration in advance, the chips are pre-conditioned to resist rotation during handling and mounting, ensuring stable and accurate placement on substrates without requiring additional alignment corrections.

Inventive Principle:

Principle #10Preliminary action

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

Achieves uniform luminance and stable mounting of light emitting chips by controlling the angles of the side surfaces, reducing rotation and irregular beam angles, and enhancing the reliability of the light emitting module.

Implementation Method 1

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

using femto-second lasers to minimize thermal damage

Methodology Applied

Scientific EffectThermal diffusion: Conduction (thermal)

Data Source

PatentUS20260011696A1Light emitting device and light emitting module including the same

Publication Date: 2026.01.08 SEOUL VIOSYS CO LTD

AI summary

A light emitting module including a mounting substrate, light emitting chips mounted on the mounting substrate, and pads, in which the light emitting chips include a first substrate, a first light emitting unit on a first surface of the first substrate, a second substrate spaced apart from the first substrate, and a second light emitting unit on a second surface of the second substrate, the first substrate includes a first side surface including a first modified surface, and the second substrate includes a second side surface facing the first side surface and including a second modified surface, the first modified surface includes first modified regions extended in a thickness direction and first ruptured regions disposed therebetween, the second modified surface includes second modified regions extended in the thickness direction and second ruptured regions disposed therebetween, and the first ruptured regions have the same width as the second ruptured regions.